Alpha male and beta male, or simply put alpha and beta, are pseudoscientific terms for men derived from the designation for alpha and beta animals in ethology. They may also be used with other genders, such as women, or additionally use other letters of the Greek alphabet (such as omega). The popularization of these terms to describe humans has been widely criticized by scientists.
Both terms have been frequently used in internet memes. The term beta is used as a pejorative self-identifier among members of the manosphere, particularly incels, who do not believe they are assertive or traditionally masculine, and feel overlooked by women. It is also used to negatively describe other men who are not deemed to be assertive, particularly with women.
The terms were used almost solely in animal ethology prior to the 1990s, particularly in regard to mating privileges with females, ability to hold territory, and hierarchy in terms of food consumption within their herd or flock. In animal ethology, beta refers to an animal who is subordinate to a higher-ranking members in the social hierarchy, thus having to wait to eat and having fewer or negligible opportunities for copulation.
In the 1982 book of Chimpanzee Politics: Power and Sex Among Apes, primatologist and ethologist Frans de Waal suggested that his observations of a chimpanzee colony could possibly be applied to human interactions. Some commentary on the book, including in the Chicago Tribune, discussed its parallels to human power hierarchies. In the early 1990s, some media outlets began to use the term alpha to refer to humans, specifically to "manly" men who excelled in business. Journalist Jesse Singal, writing in New York magazine, attributes the popular awareness of the terms to a 1999 Time magazine article, which described an opinion held by Naomi Wolf, who was at the time an advisor to then-presidential candidate Al Gore: "Wolf has argued internally that Gore is a 'Beta male' who needs to take on the 'Alpha male' in the Oval Office before the public will see him as the top dog.