According to the Encyclopedia Britannica, biological determinism, which is also known as biologism or biodeterminism, is the concept that the majority of human physical and mental characteristics are determined at conception by hereditary factors. These factors are passed from parent to child.
In the 18th and 19th centuries, biological determinism theories were based on vague, and sometimes controversial, ideas about the nature of heredity. In the 20th century, the majority of biological determinism advocates viewed undesirable traits as originating in defective traits. During the second half of the 20th century, there was a revolution in molecular genetics. Defective genes were then identified with altered sequences of the molecule of heredity known as deoxyribonucleic acid, or (DNA).