Richard Pillard (pictured) – professor of psychology in the Boston University School of Medicine – has been doing research which suggests a strong biological basis for sexual orientation.
Pilliard said through his research and personal experiences, he believes there may be a genetic basis for sexual orientation and the origin is “prenatal, partially genetic just like heterosexuality.”
Many of his own family members are gay, he said. In a study in which he was involved, Pilliard said many gay individuals interviewed did have a significant number of gay relatives in their family histories.
Another study he worked on involving twins showed that identical twins were more often either both gay or both straight.