Investigating the Role of Hormones in Theory of Mind

Article excerpt

Theory of mind (ToM) represents the ability to make inferences about the intentions, beliefs, emotional states, and likely future behavior of other individuals. It appears that, on average, girls and women have a small advantage on many ToM tasks over boys and men. The current study was designed to investigate if circulating levels of sex hormones affect ToM abilities. Study one used an experimental group of 17 women who began taking estrogen-containing oral contraceptives (OC) during the study compared to a control group who did not begin using OC. Results indicate that estrogen supplementation, at least synthetic estrogen, does not enhance ToM abilities. Study two measured circulating levels of testosterone in 57 men and 29 women via salivary assay and related them to ToM skills. Results indicate that while there is no relationship for females' level of testosterone and ToM skills (r = .10); males with higher T levels did make more errors (r = -.19) . A different pattern for males with the highest T levels was observed. Specifically, males nearing 2 SD's above the mean T levels made fewer errors (r = .20). For most males (the middle three SD'd of T levels), higher levels of testosterone are strongly associated with more errors on tests that measure ToM skills, r (47) = .33, p = .02, [R.sup.2] = .11. Reasons and theoretical implications for the overall pattern of hormonal effects are discussed.

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Theory of Mind (ToM) refers to a person's ability to think about, make intelligent inferences about, and accurately gauge another person's mind set and emotions. A person with an excellent ToM would be good at guessing what another person is thinking and would be more aware of other's feelings and motives. Theory of Mind can be considered as a module within the human mind, that is to say that there may be some set of pathways in the brain or regions of the brain that are dedicated to reading the intent and mind set of other persons (Abbas, 2006). Such an ability would very likely be useful in terms of surviving in a social society, and some (Geary, 2004; Humphrey, 1976) have argued that a ToM would have been naturally "selected for" in the course of human evolution. The discussion is not purely academic; it may have implications for understanding certain disorders. It has been argued by some that persons with autism lack a ToM entirely, while those with Asperger Syndrome (which is often thought of as a milder form of autism) have an impaired ToM. Simon Baron-Cohen, a leading researcher in this area, has argued that autism (and Asperger Syndrome) is an imbalance between two types of intelligence such that sufferers lack an ability to understand people but have an overdeveloped ability to understand and think about systems, movement and mechanical thinking.

If Baron-Cohen is correct, the sex difference in these skills and interests may be of even more interest. It has long been observed that girls and women report and illustrate more "empathic" behaviors, while boys report and show more interest in mechanical objects. For example, pre-school girls are more able to imagine other's feelings, the drawings of males contain more mechanical objects (Iijima, Arisaka, Minamoto, & Arai, 2001); males score better on spatial reasoning and mechanical aptitude tests (Geary, 1998; Kimura 1999). Of course, these differences may be cultural and/or they may be enhanced by cultural experiences. While determining whether differences in empathic thinking are all cultural, all biological or some combination of the two is not the primary focus of the proposed research, it is worth noting that some studies have documented a sex difference in the first week of life in that male infants spend significantly more time looking at a mechanical object moving, while female infants spend significantly more time gazing at a human face (Connellan et al., 2000). Whether biological or social, the empathic style and focus on other's feelings is often considered to be more female, while a mechanical, analytical style of thought is, at least somewhat more male. …