Conversely, during the first few weeks of infant life, boys are inattentive to the presence of an adult, whether speaking to the infant or not. However, baby boys tend to show more activity and wakefulness. At the age of several months, girls can usually distinguish between the faces of strangers and people they know—boys usually do not demonstrate this ability.
As infants grow into children, the differences seem to intensify and polarize. Girls learn to speak earlier than boys and do a better job of it. Boys want to explore areas, spaces and things, girls like to talk and listen. Boys like vigorous play in a large space where girls like more sedentary games in smaller spaces.