The presence of same-sex sexual behaviour was not scientifically observed on a large scale until recent times.

A homosexual is a person who engages in same-sex behavior.

The court could find that by singling out same-sex behavior Texas has violated the constitutional guarantee of equal protection.

Researchers have noted that in some cases same-sex behavior is more common for dolphins in captivity.

He noted that "the occurrence of same-sex behavior in animals provides support for the nurture side as well."

Texas is one of a few states with criminal sodomy laws that apply explicitly only to same-sex behavior.

Ford and Beach conclude that there is a "basic mammalian capacity" for same-sex behavior.

Research indicates that various forms of same-sex sexual behavior are found throughout the animal kingdom.

Information gathered from these studies is limited when applied to spontaneously occurring same-sex behavior in animals outside of the laboratory.

Attitudes toward same-sex behavior changed as Christianity became more prominent in the Empire.