From Wikipedia
Episode Two
Sex
Instincts in humans can also be seen in what are called instinctive reflexes. Reflexes, such as the Babinski Reflex
(fanning of the toes when the foot is stroked), are seen in babies and
are indicative of stages of development. These reflexes can truly be
considered instinctive because they are generally free of environmental
influences or conditioning.
Additional human traits that have been looked at as instincts are: sleeping, disgust, face perception, language acquisitions, "fight or flight"
and "subjugate or be subjugated". Some experiments in human and primate
societies have also come to the conclusion that a sense of fairness
could be considered instinctual, with humans and apes willing to harm
their own interests in protesting unfair treatment of self or others.