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Albert Stunkard and the Inheritance of Overweight
Stunkard conducted some of his most important research on obesity as an epidemiologist with the Midtown Manhattan study, where he found low-SES women were six times more likely to be obese than were high-SES women (Goldblatt et al., 1965; cf. Stunkard et al., 1972). Differences in obesity rates were also apparent among ethnic groups in the Manhattan study; for example, obesity was three times as prevalent among Italian as English women. What emerged from these data, however, was the flexibility of weight level, since members of the same ethnic groups showed considerable movement toward the American mean the longer they remained in America and the higher their socioeconomic status became. In other words, people (especially women) zeroed in on the American ideal of thinness to the extent they became integrated into the mainstream of the American middle class.
Stunkard (1976), however, expressed little faith in conventional psychological accounts of obesity and looked more toward a biological basis for overweight, even as he stressed behavior modification techniques for losing weight. Recently, Stunkard et al., (1986) elicited a tremendous media reaction when they found, in a study of Danish adoptees, that biological inheritance swamped any environmental effects in determining weight levels. Despite this discovery, Stunkard remained committed to a program of weight loss for high-risk populations who can be targeted for weight-control programs at an early age based on their parents' obesity ("Why Kids Get Fat," 1986).
Stanley Schachter and His Students and the Social Psychology of Obesity
Stanley Schachter (1968), a pioneering social psychologist, extended his work on the cognitive determination of emotions to the idea that fat people labeled their hunger based on external cues, rather than on the actual state of their stomachs. That is, instead of deciding whether they were hungry based on how full they were, they heeded such cues as the time of day or presence of inviting food to make decisions about eating. While the "externality" model of overeating initially showed promising results in a series of ingenious experiments, it later came under fire and was rejected by prominent students of Schachter's who had collaborated on much of the externality model research in the 1960s and 70s (cf. Peele, 1983). For example, Rodin (1981) repudiated the externality model of obesity primarily because there are externally oriented eaters at all weight levels.
Nisbett (1972) proposed that people's weight levels themselves (as oppose to external eating styles) are set at birth or in early childhood, so that when weight descends below this level the hypothalamus stimulates eating until the natural weight level is regained. This is one version of the so-called set-point model, which has enjoyed tremendous popularity. Rodin (1981) rejected the set-point model based on research that shows women who have lost weight do not show greater responsiveness to food cues, as set-point predicts. Rodin herself, however, emphasized physiological factors in overweight and held out the possibility that "arousal-related overeating" can be explained "without relying on psychodynamic factors" (p. 368). She also noted the self-maintaining nature of overweight, a kind of inertial adaptation by the body that might be called a model of "relative set-point" - people tend to stay at the weight level they are at.
Despite the strong emphasis on inbred and physiologic causes of overweight that characterizes the writing and research of Schachter and such Schachter students as Rodin, Nisbett, and Herman, subjects in their research often appear spontaneously to achieve self-directed weight loss and desired weight levels. For example, Rodin and Slochower (1976) found that girls who reacted strongly to external cues gained more weight than others at a food-rich camp, but that these girls frequently managed to lose much of this weight before returning home, as though they were learning how to respond to their new environment in order to maintain their preferred weight. Schachter (1982) himself discovered long-term weight loss was a relatively common event. Sixty-two percent of his ever-obese subjects in two communities who had tried to lose weight had succeeded and were no longer obese, having taken off an average of 34.7 pounds and kept the weight off for an average of 11.2 years. This result strongly contradicted previous statements by Schachter, Nisbett, and Rodin, to wit, "Almost any overweight person can lose weight; few can keep it off" (Rodin, 1981:361).
Although the dominant view of obesity - even including this group of prominent social psychologists - has insisted on the biological determination of weight level and has strongly resisted the idea of social and cognitive regulation of weight, a body of social-psychological literature supports the impact of parental socialization on eating and obesity. For example, Wooley (1972) found that both obese and normal-weight subjects did not regulate their eating based on the actual caloric content of the food subjects ate, but that they did respond to the amount of calories they thought this food contained. Milich (1975) and Singh (1973) discussed findings that indicate subjects may respond very differently in natural settings - where other matters are important to them - than they do in the typical laboratory settings where set-point and externality research have been conducted. Woody and Costanzo (1981) explored how learned eating habits (such as the types of food young boys eat) in combination with social pressures lead to obesity or its avoidance.
Stanley Garn and the Social Relativity of Eating Behavior
When leading social-psychological researchers espouse biogenic theories of obesity, we aren't likely to find much space given to models of overweight and of eating behavior based on parental and cultural socialization and value-oriented or other goal-directed behavior (cf Stunkard, 1980). The most comprehensive body of data opposed to reductionist models of obesity like set-point has been presented by an anthropologist, Stanley Garn. The primary point of departure for Garn (1985) is evaluating whether "fatness" changes or remains constant throughout the individual's lifetime, based on Garn's own and several other large-scale longitudinal investigations. Indeed, it is remarkable that both proponents of set-point and later revisions of the idea that obesity is intractable (such as Schachter, 1982) make no reference to epidemiological studies that directly test this question of constancy of weight levels and fatness.
These data contradict the set-point hypothesis in the most direct way possible. "Taking all of our data into consideration, and the more relevant data from the literature, it is clear that fatness level is scarcely fixed, even in adults. Some 40 percent of obese women and 60 percent of obese men are no longer obese one decade and two decades later. The percent of obese who become less than obese increases in succession for adolescents, for children, and finally for preschool children. Three quarters of our obese preschoolers were no longer obese when they were young adults. To the extent that fatness level is not fixed for long we may have to reconsider some of the more popular explanations for obesity" (Garn, 1985:41). The finding that the earlier the age of initial assessment the less continuity there is with adult fatness particularly contradicts assertions like those by Polivy and Herman (1983) that those who do lose weight, such as Schachter's (1982) subjects, do not have genuine set-point obesity as measured by childhood fatness.
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