In a scientific experiment, men selected women with small feet and long thighs as the most attractive, while women selected men with small wrists. Evolutionary success could explain their choices. ” Women with smaller feet have prettier faces, at least according to the men who took part in this study. So do women with longer thigh bones and narrower hips, as well as women who are taller overall. And the contest isn’t even a close one.” An evolutionary psychologist behind the experiment, Jeremy Atkinson thinks, “men find these features attractive because they serve as markers of a healthy childhood. Biologists know that stress and poor nutrition during foetal development and puberty can affect sex hormone levels and cause earlier puberty.”
A baby's first smiles are not likely an expression of inner emotion but "first smiles teach infants the positive associations attached to a smile that we adults already feel," says one professor of psychology.