A new study suggests that women may be more intuitive and less reflective than men, and this female intuition may be linked to the lower prenatal exposure to testosterone that women receive in utero.

“Women and men are different in many ways,” said author Antonio M. Espín, lecturer, Department of Economic Theory and History, University of Granada, Spain. “One traditional difference is that women appear to rely more on intuition, while a man’s mind is more analytic.”
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Intuitive thought, often referred to as female intuition, is described as an emotional way of thinking in which thoughts are processed unconsciously and automatically without much cognitive effort. In contrast, reflexive thought is more rational, requiring conscious analysis and therefore more effort.

The study involved 623 male and female students from the University of Granada who were asked to complete various questionnaires and testing, including the Cognitive Reflection Test (CRT), which measures the difference between intuition and reflection.

“Results [of the CRT] across the world have demonstrated that women tend to give more spontaneous answers in the CRT whereas men give more deliberative ones,” said lead author Antoni Bosch-Doménech, Professor, Department of Economics and Business, Pompeu Fabra University and Barcelona Graduate School of Economics, Barcelona, Spain.

“We hypothesized that sex hormones, testosterone and estrogen, might be partially responsible for the sex differences in CRT performance,” explained Espín. “Specifically, we were interested in the effect of prenatal sex hormones, which are known to exert an influence on brain organization and which are proxied by the second-to-fourth digit ratio (2D:4D; ie, the ratio between the lengths of the index and the ring fingers). The lower the digit ratio, the larger the amount of testosterone exposition in the mother’s womb.”

After the testing was completed, the participants’ two hands were scanned and their fingers were measured to determine the 2D:4D. The length of the subject’s forefinger was divided by the length of his or her ring finger on the same hand.

Espín explained that, as expected, the male students answered less automatically and more analytically than the women, who relied more on intuitive responses.

“Furthermore, the 2D:4D ratio was negatively related with answering analytically to the CRT, especially among women, so that women with a very low ratio (ie, very “masculine” ratio, reflecting a high prenatal exposure to testosterone) answered the test as analytically as did men,” he added.

Author Pablo Brañas-Garza, Professor of Behavioural Economics, Business School, Middlesex University London, United Kingdom, noted that the amount of sexual hormones received in the mother’s womb (proxied by the 2D:4D) partially determines actual behavior.

“This result is relevant since 2D:4D is completely unrelated to education or skilling acquisitions,” he said.

“The influence of prenatal events on adults’ behavior is, we believe, always intriguing. In our case, it seems particularly striking that prenatal testosterone exposure affects the way that people, especially women, answer the CRT twenty years after the fact,” said Espín.

“On the other hand, intuitive/automatic and analytic/reflective processes are involved in every decision humans make (from consumption and economic decisions to social and affective ones),” he added. “So, knowing more about the neurobiological underpinnings of such processes is of great importance for our understanding of human decision making.”

The finding that the effect of fetal hormone exposure on CRT performance appears to be stronger among women was surprising, according to Espín.

“Insofar as men are exposed to higher levels of testosterone in utero than women, this could be an indication of ceiling effects or non-linearities,” he said.

In terms of the study limitations, the participants’ “exposure to prenatal sex hormones is proxied by its putative marker 2D:4D, so measurement is imperfect and other factors may be at work. In this vein, our study is correlational, so no experimental manipulation that could have allowed for better control over other variables was employed,” said Espín.

The students’ motivations when filling out the CRT is another concern, noted Brañas-Garza.

Espín explained that one of the most important advantages of this study is its large sample size.

“Our sample of more than 600 subjects is about 5 to 10 times larger than the samples usually found in the literature on the 2D:4D digit ratio,” he said. “Also, the CRT makes a difference with respect to other tests, which are often based on self-reported answers (eg, “how often you rely on your intuition?”). Self-reports are very susceptible to subjects’ biases. These may be particularly prominent when one asks subjects about factors that are commonly associated with sex differences; exactly the focus of our research.”

This study was published in Psychoneuroendocrinology.

-Meredith Edwards White

Reference

Bosch-Doménech A, Brañas-Garza P, Espín AM. Can exposure to prenatal sex hormones (2D:4D) predict cognitive reflection? Psychoneuroendocrinology. 2014 May;43:1-10. doi: 10.1016/j.psyneuen.2014.01.023. Epub 2014 Feb 6.