Some psychologists interpret subtle clues, thus to deepen their understanding of human nature. Here are two examples.
“The Clock Is Ticking,” Justin H. Moss and Jon K. Maner [pictured here], Human Nature, epub April 2014. The authors, at Florida State University [Professor Maner has since moved to Northwestern University], explain:
The “biological clock” serves as a powerful metaphor that reflects the constraints posed by female reproductive biology. The biological clock refers to the progression of time from puberty to menopause, marking the period during which women can conceive children. Findings from two experiments suggest that priming the passage of time through the sound of a ticking clock influenced various aspects of women’s (but not men’s) reproductive timing….
Participants were randomly assigned to complete measures in either the presence or absence of a ticking clock (a small white kitchen timer). The clock was located on a table and was both visible and audible to the participant. Participants in the control condition completed the survey in a silent room… [They then answered four survey questions]: (1) “How old do you think you’ll be when you get married?” (2) “If you were to get married, in how many years from now do you think you’ll want to get married?” (3) “How old do you think you’ll be when you have your first child?” (4) “If you were to have children, in how many years from now do you think you’ll want to have your first child?”
… In conclusion, the current research suggests that priming the passage of time via the sound of a ticking clock affects important aspects of social decision-making.
Professor Maner is also an expert on the significance of the relative lengths of a person’s second and fourth fingers:
“Confronting intrasexual rivals: 2D:4D digit ratio predicts behavioral and endocrinological responses to infidelity threat,” Jon K. Maner, S. L. Miller, J. M. Coyle and M. P. Kaschak, Social Psychological and Personality Science, vol. 5, 2014, pp. 119-128.