Neurobiologist Robert Sapolsky constructed a reproductive spectrum with opposite poles being tournament species, in which males compete fiercely for reproductive privileges with females, and pair bond arrangements, in which a male and female will bond for life.
"[Brad] realizes the huge age difference and that everyone would look at the relationship as a midlife crisis mistake," the source explained.
Dating as an institution is a relatively recent phenomenon which has mainly emerged in the last few centuries.
From the standpoint of anthropology and sociology, dating is linked with other institutions such as marriage and the family which have also been changing rapidly and which have been subject to many forces, including advances in technology and medicine.
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She was recently cast in the lead role of Starz's upcoming TV series "Sweetbitter," which is being produced by Pitt. He went out of his way to cast her," the source added.
Thus, the concept of marriage is changing widely in many countries.