Deconstructing the “Two Factors”: The Historical Origins of the Schachter–Singer Theory of Emotions

The Psychology of Affiliation

Schachter’s 1959 The Psychology of Affiliation and his early 1960s experiments with Singer (Schachter & Singer, 1962), Wheeler (Schachter & Wheeler, 1962), and Latané (Latané & Schachter, 1962) occurred during the post-Second World War, Cold War period. This period was characterized by a general suspicion of emotions. In the social sciences of liberal democratic societies, the emotions were pathologized as the irrational element that was responsible for the horrors of the Holocaust and the rise of fascist regimes (Biess & Gross, 2014). This suspicion of emotions went hand-in-hand with Cold War concerns regarding emotional manipulation and contagion: with Hidden Persuaders, brain-washing, and motivation research à la Ernest Dichter (Packard, 1957; Schwarzkopf & Grie, 2010; Seed, 2004). This emotional background of postwar, Cold War U.S. society is significant since it was a major factor in Schachter’s decision to go to MIT, where Kurt Lewin had established the Research Center for Group Dynamics. As Schachter reminisced, the decision to go to MIT was a “mindlessly idealistic decision,” which was instigated by the “hopelessly appealing” idea “after two decades of depression, fascism, and war” that “psychology might actually be useful in the study of social problems” (Schachter, 1989, p. 452). Bibb Latané, one of Schachter’s students, also reminisced in similar terms regarding this period:

[I]n those days when the threat of nuclear war was still fresh and unfamiliar, it was a truism that the security of the world depended on advances in social science comparable to the frightening strides being taken by the physical sciences. (Latané, 1987, pp. 66–67)

Emotional conformity, emotional influence, and emotional manipulation were on these researchers’ minds.

In The Psychology of Affiliation: Experimental Studies of the Sources of Gregariousness (1959), Stanley Schachter studied the social conditions that increased “affiliative tendencies.” Schachter’s study took off from Festinger’s “drive for self evaluation” theory (Festinger, 1954). This theory stipulated that “self evaluation can only be accomplished by means of comparison with other persons” (Schachter, 1959, p. 3). One’s opinions and one’s abilities were thus evaluated in reference to other people. This new theory of self-evaluation in terms of the social group had underpinned a new “body of research on social influence” (Schachter, 1959, p. 4). Schachter’s objective was to expand Festinger’s original model—which appertained to opinions and behaviors—to the emotions. He studied the “evaluative need” to appraise one’s own emotions “by reference to other people.” This basic need to evaluate one’s own emotions by reference to the group explained the homogenization of emotions among group members during states of ambiguity and anxiety.

In his first series of experiments, Schachter (1959) created high- and low-anxiety states in a group of college “girls” and studied the correlation between levels of anxiety and the “affiliative tendency”—the wish to be together with others. One of his major interpretations from these preliminary studies on anxiety and affiliative tendency was that,

[I]n a novel, emotion-producing situation, unless the situation is completely clear-cut the feelings one experiences or “should” experience may not be easily interpretable, and it may require some degree of social interaction and comparison to appropriately label and identify a feeling. We are suggesting, of course, that the emotions are highly susceptible to social influence. (Schachter, 1959, p. 26)

Following additional experiments on affiliative tendency and anxiety, and a series of studies on ordinal position, anxiety, and affiliative tendency, Schachter (1959) studied the relationships between hunger and affiliative needs in college “males.” This latter experiment was designed in order to ascertain whether drives, in addition to emotions like anxiety, could also be correlated with affiliative need. His tentative conclusion was that “Hunger appears to be similar to anxiety” (Schachter, 1959, p. 96).

In a following series of experiments, Schachter (1959) distinguished between the function of “togetherness” in reducing anxiety versus its function in homogenizing the emotions through self-evaluation in reference to the emotions of others. This study was undertaken with his graduate student Lawrence Wrightsman (Wrightsman, 1959), and also appeared in a separate publication (Wrightsman, 1960). The major conclusion from this study was that for

[S]tates of anxiety . . . there is good evidence that social-influence processes are operative and that the individual evaluates his own feelings by comparing himself with others. . . . In short, there is every indication that the conformity evidenced . . . is a manifestation of a genuine individual need for appraisal of a state of emotion or feeling. (Schachter, 1959, p. 125)

Following this major conclusion of the experimental part of his monograph, Schachter (1959) introduced several propositions in his concluding chapter on “Social Determinants of Emotional State.” He opened this last chapter by shifting his discussion to the literature on the physiological correlates of emotions. He observed that “much research has failed to reveal clearly distinguishable physiological correlates for the various emotions” (Schachter, 1959, p. 126). Thus, in explaining “What does determine whether a person will label his feelings as anger, vexation, impatience, or fury . . . most writers . . . define emotion in terms of both physiological and situational or cognitive factors” (Schachter, 1959, pp. 126–127). In presenting the cognitive-situational model of emotions, Schachter quoted directly from the monographs by Young (1943) and Ruckmick (1936)—“two major treatises on emotion” that emphasized the cognitive element. Schachter concluded from this literature that “cognitive factors [are] . . . the determiners of the appropriateness of an emotion; one labels, interprets, and identifies the stirred-up state characteristic of emotion in terms of the characteristics of the precipitating situation and of one’s apperceptive mass” (Schachter, 1959, p. 127).

Why did Schachter shift and appeal to the literature on the “cognitive” element in emotion in the concluding chapter of his monograph on affiliation, evaluative needs, and social comparison and influence? Schachter’s monograph (1959) does not provide an answer to this significant question. The rationale for this shift was elaborated in Wrightsman’s publication (1960), which was a condensed version of his doctoral dissertation with Schachter. The turn to the cognitive element in emotion in the affiliation studies did not stem from an engagement with the James–Lange (James, 1884; Lange, 1885) theory and controversy. It was, rather, necessary for justifying the extension of Festinger’s theory of “drive for self evaluation” by “comparison with other persons” to the realm of the emotions (Festinger, 1954, p. 138). Festinger’s theory, which underpinned Schachter’s project and his and Wrightsman’s experiments, appertained only to opinions and behaviors.

As Wrightsman explained:

One of the purposes of this study is to determine whether the emotion of anxiety is similar to abilities and opinions in being evaluated in ways subject to influence by the responses of others. . . . But is it correct to assume that felt emotions are, in part, cognitively determined, and that there is a conceptual similarity between the determinants of emotions and the determinants of opinions? The tenor of much thinking about the emotions seems to suggest that both physiological and cognitive processes determine experienced emotions. (Wrightsman, 1960, p. 217)

Immediately following this statement, Wrightsman (1960) elaborated on the cognitive element in emotion, citing from Ruckmick’s (1936) Psychology and referring to Young’s (1943) monograph, in what was almost an exact duplicate of Schachter’s corresponding paragraphs in the Affiliation monograph (Schachter, 1959, p. 127; Wrightsman, 1960, p. 217). The only significant difference between Wrightsman’s allusion to this literature and Schachter’s near duplicate text was the omission in Schachter’s monograph of the rationale and motivation for the inclusion of this literature on the cognitive element in emotion. As Wrightsman continued: “To the extent that cognitive factors do determine emotional states, emotions, like opinions, may be expected to be susceptible to social influence” (Wrightsman, 1960, p. 217).

Wrightsman returned to the cognitive in the concluding sections of his publication:

Festinger’s scheme for explaining self-evaluation through a social comparison process is useful for the emotion of anxiety as well as for opinions and abilities. Can it then be concluded that because cognitive factors have some effect in determining [anxiety] . . . that the emotions in general are also susceptible to social influence? . . . It was concluded that a person does evaluate his level of anxiety through the process of social comparison and that level of anxiety shares with opinion the feature of being partially determined by cognitive processes. (Wrightsman, 1960, p. 221)

Emotion became cognitive because it behaved like opinion in terms of Festinger’s (1954) scheme and Schachter (1959) and Wrightsman (1959) appealed to the literature on the cognitive in emotion in order to extend Festinger’s model of opinion to emotion. This missing rationale in Schachter’s monograph also clarifies Schachter’s suggestion in the opening pages of his 1959 monograph that “one broadens this ‘drive for self evaluation of opinions and abilities’ into a more general ‘drive for cognitive clarity’” (1959, p. 5).

Back in Schachter’s monograph, and after presenting the literature on the cognitive element in emotion (minus the rationale), Schachter distinguished between cases in which the precipitating situation was completely “clear-cut and recognizable” and cases of “disturbing situations which are more ambiguous and unfamiliar” (Schachter, 1959, p. 127). In these latter cases,

[W]hen the precipitating situation is ambiguous or uninterpretable in terms of past experience, again pressures arise to establish a social reality. And since emotion producing situations are often novel and outside the realm of our past experience, it could be expected that the emotions would be particularly vulnerable to social influence. (Schachter, 1959, p. 128)

This preliminary model of “pressures . . . to establish a social reality” during emotional ambiguity, through a process of social comparison and social influence, was only “a point of view and one that is peculiarly marked with problems” (Schachter, 1959, p. 128). Schachter suggested several avenues for future research, one of which “will require direct manipulation of the evaluative need” (Schachter, 1959, p. 132).

In this concluding chapter, Schachter also suggested that his discovery of a vulnerability to “emotional influence” during ambiguity “will eventually help us understand phenomena of emotional contagion such as panic and riots” (Schachter, 1959, p. 128). Throughout his affiliation monograph, Schachter (1959) did not mention the studies by Marañón (1924), Cannon (1927, 1931), Landis, Hunt, and Cantril (Cantril & Hunt, 1932; Landis & Hunt, 1932); and he did not mention the sympathetic or autonomic nervous system, adrenalin, or the James–Lange theory and debate.

The Schachter–Singer Experiment

By February of 1961, the experiments with Singer (Schachter & Singer, 1962), Wheeler (Schachter & Wheeler, 1962), and Latané (Latané & Schachter, 1962) were already completed and written up (Schachter, S., 1961, Schachter to R. Solomon, February 15, 1961). Schachter’s initial intent had been to publish the three articles together, rather than as separate pieces, as they ultimately appeared. As Schachter explained to Richard Solomon, editor of Psychological Review, the three articles should have appeared together in a monograph, but he wanted to give each of the “kids” coauthorship on the individual studies (Schachter, S., 1961, Schachter to R. Solomon, February 15, 1961). If Solomon would have agreed to publish the three pieces together, Schachter would have liked the three articles to appear together under the “general heading ‘Cognitive, Social and Physiological Determinants of Emotional State’ and to retitle the Schachter–Singer article ‘The interaction of Cognitive and Physiological Determinants of Emotional State’” (Schachter, S., 1961, Schachter to R. Solomon, April 24, 1961). Solomon declined (Solomon, R., 1961, Solomon to S. Schachter, May 3, 1961). The general heading remained the title of Schachter and Singer’s (1962) article. The proposed title for Schachter and Singer’s article became the modified title of Schachter’s article of 1964 (Schachter, 1964).

The Schachter–Singer experiment enacted Schachter’s—and Wrightsman’s—major conclusions from The Psychology of Affiliation (1959). Let us examine the Schachter–Singer experiment from this perspective. First, we can note the similarities between the original manuscript that Schachter and Singer sent to Psychological Review and the published version. Both versions began by positioning the experiment in terms of James’s (1884) theory and its legacy, and both versions mentioned Cannon (1927, 1931) and Marañón (1924). However, and as Ladd Wheeler recently put it in an email to the author: “I don’t think that the James–Lange controversy was important to us” (L. Wheeler, personal communication, January 20, 2015). Indeed, it was not. Though Schachter and Singer positioned their article in these terms and introduced their published study as directly following on and semi-inspired by the major experiments that tested the James–Lange theory prior to their study, by Cantril and Hunt (1932) and Landis and Hunt (1932), the original manuscript made no reference to these studies (Schachter & Singer, n.d.). The references to these latter experiments were suggested by the reviewer, who had handwritten his comments on the margins of the original manuscript (Schachter & Singer, n.d.). The anonymous reviewer had requested that “the work of other authors who have looked into the situation for the factors which differentiated the emotions ought to be included in at least brief summary form” (Solomon, R., 1961, Solomon to S. Schachter, April 17, 1961). These latter famous experiments studied the effects of injecting adrenalin into human subjects in the context of the James–Lange theory and controversy.

We can recall that James had argued that,

Our natural way of thinking about . . . emotions is that the mental perception of some fact excites the mental affection called the emotion, and that this latter state of mind gives rise to the bodily expression. My thesis on the contrary is that the bodily changes follow directly the PERCEPTION of the exciting fact, and that our feeling of the same changes as they occur IS the emotion. (James, 1884, pp. 189–190)

In their adrenalin injection experiments, Cantril and Hunt and Landis and Hunt injected adrenalin into humans in order to produce “bodily changes” without a preceding mental affection, as James (1884) had put it, and asked their subjects to introspect as to whether the bodily changes, in and of themselves, induced an emotion (Cantril & Hunt, 1932; Landis & Hunt, 1932).

The only adrenalin injection experiment that did appear in the original manuscript was Gregorio Marañón’s 1924 study, “Contribution à l’étude de l’action émotive de l’adrenaline” (Marañón, 1924). Schachter could not read this “obscure paper written in French”—as Bibb Latané would put it—in the original, and Latané and Schachter’s “(French) first wife” translated it into English (Latané, 1987, p. 70). Why did Schachter and Singer rely exclusively on a French publication from the 1920s, which they could not read in the original language, rather than on the articles by Cantril and Hunt (1932) and Landis and Hunt (1932)? This is all the more perplexing, since the studies by Cantril and Hunt and Landis and Hunt were written in English, were highly cited articles in this debate, provided more up-to-date information, and appeared in prominent English-language venues: Cantril and Hunt’s article appeared in The American Journal of Psychology, and Landis and Hunt’s one appeared, in fact, in Psychological Review. In addition, Schachter had cited Ruckmick’s Psychology (1936) in his Affiliation (1959) monograph. He could not have failed to come across these experiments in reading Ruckmick. I suggest that when Schachter read Ruckmick’s Psychology and adopted the cognitive view of emotion he did not register these articles since he did not have the James–Lange theory in mind, but only the extension of Festinger’s scheme to emotion in the context of his affiliation research. How Schachter came to read Marañón’s article remains an open question.

Schachter and Singer were also unaware of Hunt, Cole, and Reis’s 1958 article, which would appear only in the published version. As Schachter wrote to Richard Solomon, in thanking him for the reviewer’s and for his comments: “They were more than helpful, steered me to the Hunt paper, which I hadn’t known about” (Schachter, S., 1961, Schachter to Solomon, April 24, 1961). Schachter and Singer introduced this latter article in the published version as the most “explicit” example of a study that preceded theirs and which had already “suggested that situational factors should be considered the chief differentiators of the emotions” (Schachter & Singer, 1962, p. 381 Footnote 4). This article, like those by Cantril and Hunt (1932) and Landis and Hunt (1932), could not have steered them to their experiments.

There were several additional criticisms of the manuscript. These included a request that “Schachter and Singer might also be somewhat more careful in the way in which they use the terms activation, arousal, and excitement”; and that they should “guard against the assumption that their reports of emotion and their behavioral indices of emotion are full-fledged emotions” (Solomon, R., 1961, Solomon to S. Schachter, April 17, 1961). The reviewer was also critical of the fact that they had not included a “misinformed” group in the epinephrine anger situation (Solomon, R., 1961, Solomon to S. Schachter, April 17, 1961). “Unfortunate!”—the reviewer remarked in pencil on the manuscript (Schachter & Singer, n.d.).

Following the emendations of and additions to their original manuscript, Schachter and Singer presented seven different experimental interventions. These interventions included: the injection of epinephrine or placebo; informing, not informing, and misinforming the subjects regarding the effects of epinephrine; and the induction of two emotions: euphoria and anger.

In the subsection on “Producing an Emotion-Inducing Cognition,” Schachter and Singer (1962) presented the procedure for inducing the two emotions of euphoria and anger. After reiterating again the centrality of the “cognitive factors” in emotions, they immediately explained that,

There are, of course, many ways to induce such states [of emotion]. In our own program of research, we have concentrated on social determinants of emotional states and have been able to demonstrate in other studies that people do evaluate their own feelings by comparing themselves with others around them. . . . In this experiment we have attempted again to manipulate emotional state by social means. (Schachter & Singer, n.d., p. 9; 1962, p. 383)

Years later, Schachter would reiterate and emphasize both the intimate links between the Affiliation (1959) monograph and the experiment with Singer, and the centrality of “social influence” in the experimental design of the Schachter–Singer experiment:

It seemed to me that the findings of the affiliation experiments could be interpreted as an indication that the emotions were as vulnerable to social influence as were the opinions and abilities (see Festinger, 1954). This, of course, was simply a point of view, not even a hypothesis. (Schachter, 1989, p. 459)

The experimental protocol with Singer was designed in terms of the “social influence” approach. In the euphoria experiment, a stooge—Ladd Wheeler, according to the original and unpublished design of the protocol—was “trained to act euphorically” (Schachter & Singer, 1962, pp. 383–384). In acting euphorically, Wheeler built and flew paper airplanes, tried a hula hoop, etcetera, in the presence of the subject. He did not explain why he was euphoric to the subject, he only behaved euphorically. The euphoric situation was thus a situation of pure “social influence”—as Schachter referred to such situations in his Affiliation (1959) study. The stooge’s euphoric behavior induced (or not) a euphoric behavior and/or emotion in the subject, depending on the conditions of the experiment (epinephrine/placebo; informed/uninformed/misinformed). This type of set-up, in which emotional manipulation was enacted through social influence, characterized the affiliation studies. The mechanism, as Schachter had elaborated in the affiliation studies, was as follows: an ambiguous state, or being “stirred up,” exerted a pressure to establish a social reality, which increased “social influence” and homogenization of emotions. The injection of epinephrine in this case either produced ambiguity or a state of being stirred up or of anxiety—all situations that Schachter had previously created in his affiliation study.

The anger situation from this perspective was not entirely analogous to the euphoric one, despite their presentation as parallel enactments in Schachter and Singer’s (1962) publication. In the anger situation, the stooge, who had been “trained to act in an angry fashion,” (Schachter & Singer, 1962, p. 384) not only behaved as if he was angry, but he also provided the subject with an explanation, a rationale, for why he was angry. The stooge in this second situation referred out loud to specific questions on the questionnaire that he and the subject were instructed to fill in (“How many times each week do you have sexual intercourse?”; “With how many men (other than your father) has your mother had extramarital relationships?”; “What is your father’s average annual income?” [p. 385]), and presented them to the subject as ridiculous, insulting, or intrusive. The anger situation was thus a mixture of Schachter’s “social influence” mechanism and a new cognitive element—an explanation that was provided explicitly by the stooge and explained why one was “stirred up.”

Following the description of the experiments, Schachter and Singer (1962) presented and discussed their results. Two issues remained unresolved. The first was the failure of the experiment to demonstrate the expected difference between the placebo and epinephrine-injected subjects; the second was the failure of the experiment to demonstrate the expected difference between epinephrine-injected informed and uninformed subjects. In resolving these particular issues, Schachter codesigned three additional experiments with, respectively, Wheeler (Schachter & Wheeler, 1962), Latané (Latané & Schachter, 1962), and Singer (Singer, 1961). He also codesigned a fourth experiment with Wheeler. This latter experiment was a comparative study of injecting epinephrine and norepinephrine. It was never realized since Schachter left for Columbia (Wheeler, 1987).

In the first experiment with Wheeler (Schachter & Wheeler, 1962), which immediately followed the Schachter–Singer (1962) experiment, Schachter and Wheeler sought to eliminate the possibility that placebo-injected subjects were aroused during the experiment, despite not receiving an injection of epinephrine. This would explain the failure to demonstrate the expected difference between them and epinephrine-injected subjects. Schachter and Wheeler controlled for this possibility by injecting chlorpromazine, a sympathetic blocking agent, into some of the subjects. In inducing emotions inside the laboratory, Schachter and Wheeler eliminated the elaborate and cumbersome stooge protocol and induced emotions by screening a scene from a slapstick movie. This change enacted inside the laboratory the complete shift that had occurred in the conception of emotions: from Schachter’s social influence theory, which worked by social comparison and homogenization of emotions across individuals (i.e., with the stooge), to a cognitive theory, which did not work by emotional “contagion” and comparison, but by having (or not having) an explanation for the “stirred-up visceral state,” as Singer explicated the meaning of “cognition” in his 1961 doctoral dissertation with Schachter (Singer, 1961, p. 7).

As Wheeler put it in an email to the author in referring specifically to this very point:

Stan originally thought of emotions as requiring social stimuli to pair with the arousal, but he realized as soon as the Schachter/Singer research was done that all that was needed was an explanation of the arousal. That didn’t have to be social; any cognition would do. That is why Schachter/Wheeler did not use social stimuli that would allow contagion [emphasis added]. A funny movie provided an explanation but was not social. Jack Carson was funny, but he wasn’t laughing. (L. Wheeler, personal communication, January 20, 2015)

The shift from a social influence to a cognitive framework, from affiliating with a euphoric stooge (Schachter & Singer, 1962) to seeing a funny slapstick movie (Schachter & Wheeler, 1962), was not designed, as one might have thought, in order to exclude a “social influence” theory of homogenizing emotions. It was simply assumed by the end of the first experiment; and now that it was assumed, it was simply more expedient,

It was more efficient experimentally to use a movie rather than a stooge as in Schachter/Singer. I think we just assumed that the movie would work as well as a social stimulus. If we were setting out to prove that, I think we would have said so in the article. (L. Wheeler, personal communication, January 27, 2015)

Wheeler “watched many funny movies to find one that was funny but not too funny.” However, he “was never very convinced” by his experiment, “because the main support was belly laughs, and I feared they might be related to the physically energising effects of epinephrine as opposed to chlorpromazine, quite apart from any emotional effect” (L. Wheeler, personal communication, December 29, 2014).

Bibb Latané’s rat experiment with Schachter (Latané & Schachter, 1962) and, more so, Singer’s doctoral dissertation using rats (Singer, 1961), also sought to eliminate or verify the “artifact[s],” as Singer put it (pp. 7–9), that were observed in the Schachter–Singer experiment. The shift from human subjects to rats in Singer’s dissertation was designed primarily in order to explain the failure to observe the expected difference between epinephrine-injected subjects who were informed regarding its effects and epinephrine-injected subjects who were not informed. Singer selected rats for his experiments in order to nullify the possibility that epinephrine-injected subjects who were not informed nonetheless made the connection between the injection and their physiological state of being stirred up. This self-informing possibility was eliminated since rats could not self-inform—so Singer reasoned. In his dissertation, Singer also injected high and low doses of epinephrine in order to study the effects of different levels of adrenalin (different levels of autonomic arousal); and he attempted to come to terms with the reports by Walter B. Cannon (1927) and Charles Scott Sherrington (1900) that sympathectomized animals continued to exhibit normal emotional behaviors, despite the absence of physiological arousal.

The shift to rats, to Skinner boxes and avoidance learning, severed any remaining ties with the social affiliation paradigm of self-evaluation in terms of the social group and the centrality of social influence in determining one’s emotions. The shift to rats also highlighted Schachter’s noncommitment to one school or methodology in the study of emotions. He appealed to the subjective self-reports of human subjects, to behaviorist approaches and practices, and to physiological experiments on rats. The conjoining of what others perceived as incompatible methodologies and schools of thought by the social psychologist Schachter found its parallel in the no less significant studies of another famous and contemporaneous social psychologist—James Olds (1958), who inaugurated the modern study of the neurophysiology of “reward” and “pleasure.” Like Schachter, Olds conjoined seemingly incompatible approaches—appealing to subjective experiences, like “pleasure,” assuming a behaviorist paradigm and terminology, and incorporating physiological experiments on rats (Dror, 2016). Despite their shared disciplinary identity, shared eclecticism, and the contemporaneousness of their studies, the Schachter–Singer science of emotions developed in complete isolation from the contemporaneous developing brain sciences of emotions.

Adrenalizing Emotions: Sympathetic Arousal in the Two-Factor Theory

The major new ingredient in Schachter’s experiment with Singer seen in light of his previous research on affiliation was his incorporation of the sympathetic nervous system and adrenalin. Perhaps Schachter had intended to emphasize this shift, in writing to Richard Solomon that he would have preferred to title his first experiment with Singer “The interaction of Cognitive and Physiological Determinants of Emotional State,” if Solomon would have agreed to publish the three articles together (Schachter, S., 1961, Schachter to R. Solomon, April 24, 1961).

The adrenalin element came most directly and ostensibly from Marañón’s 1924 “Contribution à l’étude de l’action émotive de l’adrenaline”; perhaps also from Ruckmick. This article shifted Schachter’s attention to Cannon, adrenalin injection experiments, the sympathetic nervous system, and to the James–Lange theory and controversy. As Walter B. Cannon had already written to Marañón, in reference to Marañón’s studies, several decades prior to Schachter and Singer’s discovery of Marañón:

Here we have the typical disturbance of the organs aroused by emotional excitement without a primary emotional excitement to initiate the disturbance. The bearings of these observations on the James–Lange theory of the emotions is obvious, as you have noted. I only wish that my good friend, Professor James, were now alive, to see what his reactions would be to the new evidence. (Cannon, W. B., 1923, Cannon to G. Marañón, July 12, 1923)

Marañón’s 1924 study, on which Schachter and Singer would draw, was only one in a series of experiments that Marañón conducted on the emotions, physiology, and clinical medicine (Marañón, 1919, 1921, 1924). In his 1924 experiment, Marañón extended his previous research on the relationships between the emotions and hyperthyroidism and on adrenalin. Marañón created the embodiments of emotions by injecting adrenalin and studied the relationships between these embodiments and experienced emotions, focusing on hyperthyroidism, menopausal women, a variety of pathologies, and “normal” individuals who were in a state of heightened “affective excitement.” These latter diverse states, according to Marañón, were all predisposed to react emotionally and were thus prone to develop emotions after the injection of adrenalin. It was only in the concluding section of this wide-ranging 1924 study that Marañón reflected on the significance of his physiological and clinical studies for the James–Lange theory (James, 1884; Lange, 1885). Here, he proposed his own theory of emotions (for Marañón’s specific theory of emotion, see Cornelius, 1991). Schachter and Singer’s (1962) presentation of Marañón’s 1924 article exclusively in terms of the James–Lange theory reframed and obfuscated the wide-ranging physiological and clinical contexts of his adrenalin injection experiments.

The shift to adrenalin was highly significant for several reasons. The first was the displacement of the social by the pharmacological. Instead of creating the “evaluative needs” via social situations, Schachter and Singer created evaluative needs by injecting adrenalin. The second important signification pertained to the physiological and cultural meanings of adrenalin during the mid-20th century. Adrenalin was the hormone of the fight-or-flight response. In the field, it had been studied most frequently in men who were engaged in masculine endeavors, like wars and vigorous sports. Cannon’s (1915) extensive and renowned studies of the physiology of emotions and adrenalin inside the laboratory had focused practically exclusively on animals engaged in fights, and on fear and rage.

In the cultural-gendered contexts of the 1950s and 1960s, the warring-masculine associations of adrenalin were partly and implicitly integrated into the experiments. With the shift to adrenalin, Schachter shifted from a subject pool of mostly—but not exclusively—college “girls” to a pool of exclusively college “males”: “Schachter maintained, in several contexts, that he had not found affiliative behavior in men under stress and, consequently, conducted his subsequent studies on affiliation using females only” (Taylor et al., 2000, p. 418, Note 15). Alternatively, and as Ladd Wheeler speculates in a related vein: “Stan may have used females in the affiliation work because he thought they would be more anxious or admit more anxiety about electric shocks” (L. Wheeler, personal communication, March 30, 2015). ¹

The association of adrenalin with the fight-or-flight response, with fear and rage, also explains particular elements of the experiments with Singer and Wheeler. Singer’s doctoral dissertation (1961) using rats included as a crucial control injecting adrenalin without manipulating the rats. This element controlled for the possibility that adrenalin induced fear, in and of itself. More significantly, these associations explain why Schachter and his students deliberately expanded the purview of their experiments to include nonbelligerent emotions in addition to studying the classical emotions of fear and rage. This expansion of the hormone of fight-or-flight to other emotions, to amusement (in Schachter and Wheeler’s [1962] experiment) and to euphoria and laughter (in Schachter and Singer’s [1962] experiment), was ostensibly expressed in Singer’s dissertation, which assumed/asserted that sympathetic arousal was constitutive of emotion qua emotion: “sympathetic arousal does seem to be common to all those things which we called emotions” (Singer, 1961, p. 3).

The incredibility and significance of this statement can only be appreciated from an historical perspective that reflects back to the 19th century, when it was physiologically, as well as culturally, inconceivable that every emotion was embodied in terms of sympathetic activation; and that there were no embodied distinctions between, for example, the emotion of shame and the emotion of rage; that the blushing body was indistinct from the raging body (Dror, 2010).

During the early 20th century, when Walter B. Cannon (1915) began his famous studies on the physiology of emotions and adrenalin, he focused on the “strong” emotions, as he explicitly put it. Though Cannon had argued decades prior to Schachter and Singer that adrenalin was present during the nonbelligerent strong emotions, including “joy,” he never attempted to produce great joy inside his laboratory and measure concomitant levels of adrenalin. Inside his laboratory, adrenalin was a product of the emotions of “rage” and “fear.” More significantly, Cannon was adamant regarding the distinction between the “strong” emotions and the “soft” emotions, and between emotions in which the sympathetic system was activated (“strong”) and those in which the parasympathetic system was activated (“soft”; Dror, 2014).

During the first half of the 20th century, the preliminarily narrow span of adrenalized belligerent emotions progressively expanded to encompass numerous nonbelligerent emotions. These latter were adrenalized. Everyday social activities, like consumerism, a game of poker, a movie, reading the Bible, listening to music, and playing a game of chess; and a broad spectrum of emotions, including love, jealousy, worry, and joy, were studied in terms of an adrenaline-sympathetic reaction (Dror, 2009).

Schachter and Singer’s (1962) experiment took this progressive historical transformation of the emotions one step further. Schachter and Singer defined sympathetic nervous system activation as an essential and obligatory element of every emotion qua emotion. This is all the more noteworthy, since Schachter and Singer only injected adrenalin, yet they theorized emotion in terms of “sympathetic nervous system” activation. Schachter and Singer’s model/definition of emotion was the end product of a longer historical process. ²

The extension of sympathetic activation to all emotions was contrary to developments of the 1940s. During the 1940s, Cannon’s (1915) emphasis on the sympathetic nervous system was challenged by the discovery of parasympathetic (Kling, 1933) involvement in the strong emotions. This shift to or recognition of the parasympathetic nervous system appeared in a growing number of emotion-focused studies (e.g., Gellhorn, Cortell, & Feldman, 1941; Kling, 1933). In addition, basic embodiments of affective reactions, including blushing, tears, and erection, were parasympathetic according to contemporary physiology. Despite this overt tension, the experimenters of the early 1960s and their followers defined sympathetic nervous system activation as an essential element of every emotion qua emotion.

Concluding Observations

My primary aim in this contribution has been to present a microscopic examination of a particular set of elements in a number of experiments. The cognitive turn in emotions, however, can be positioned in light of a macroscopic perspective, and in terms of major transformations in Western culture. This macroscopic perspective highlights developments that provided the cultural conditions for the very possibility of a cognitive dimension in emotion. One of these significant transformations occurred during the 18th century, with the shift from a vocabulary of premodern “passions” to a vocabulary of modern “emotions.” As Philip Fisher has argued, the 18th century shift from premodern “passions” to modern post-18th-century Humeian “emotions,” “feelings,” and “moods” marked an important moment in the redesign of inner life (Fisher, 2002):

The most significant historical redesign of inner life have taken place within modernity around the vocabulary of emotions, feelings, and moods . . . what typifies the modern term “feeling” . . . is the ability to be and not to be . . . to participate and to be exempt from the experience. This is the basic mark of thought. To imagine oneself in another state while enjoying the state that one is in as a result of the act of imagination points to a distinction between the self and its states, even within the moment of emotion. And it is this distinction that is at the heart of the idea of the state that we call “feeling.” (2002, p. x)

The 18th-century shift from “passions” to feelings and emotions signified that the moment of “passion” did not totally dominate and overwhelm the self; that the new emotional—rather than passionate—self existed in multiple and concurrently existing states. This possibility of a “cognitive” that coexisted with “emotion” became part of emotion itself in the 20th century—in a post-“passion” culture of the “emotions.”

The Schachter–Singer experiment can also be contextualized in light of the immediately preceding shift from peripheralist explanations for and models of the basic drives to centralist models and explanations. This major shift ended a protracted debate with respect to the locus of the basic drives, like hunger and thirst. During the 1950s, a centralist consensus was consolidated and the basic drives were (re)located to the hypothalamus. The shift to the brain and the decline of peripheralist models was thus part of a more general development in physiology (Stellar, 1954).

The Schachter–Singer experiment (1962) is in part a history of how a social influence model became generalized to a cognitive view. The developments that ensued from the Schachter–Singer experiment highlight this schizoid origin/identity of the theory. On the one hand and in psychology, the “cognitive” element instigated numerous studies on attribution and misattribution. On the other hand and in sociology, the “social” element, which had somewhat receded into the background, returned in a new guise. It became apparent in the emergent sociology and anthropology of emotions of the late 1970s and early 1980s. The new social constructionist paradigm of emotions in the social sciences drew directly on Schachter and Singer’s 1962 cognitive-physiological theory of the emotions (and much less so, on Schachter’s [1959] explicit “social” theory of emotions of the late 1950s). Schachter and Singer’s theory of emotions became a new basis for defining emotion and for a social constructionist—symbolic interactionist—approach to emotion (Shott, 1979).

In closing, I note that Schachter was furious with the published version of his coauthored article with Singer (1962), as he explained in his “first outraged letter” to Richard Solomon. There were several issues, but the most outrageous one was with respect to Tables 6–9. These tables summarized, respectively, the results of “self-informed” subjects and of subjects who “give indication of sympathetic activity.” As Schachter wrote to Solomon: “Since the paper has appeared students have tittered at me, my colleagues look down at their plates.” The most serious issue, among several, was that Tables 6–9 were totally misleading. The “notation ‘ns’ in the p column,” as Schachter explained, “is meaningless. Nothing was tested” (Schachter, S., 1962, Schachter to R. Solomon, May 3, 1962). Nothing was tested, as Schachter explained, since it was nonsense to calculate a “p” value where the publisher had mistakenly indicated a p-value that was “not significant.” One can only wonder what countless readers of the Schachter–Singer article understood in reading the “ns” notation in the “p” column of Tables 6–9, and to what good uses this copy-editing blunder has been put to by researchers since then.