Biological theories⁷

• Some investigators speculate that attraction to minors has a neurohormonal cause, possibly with an evolutionary basis. One theory involves the process of brain masculinization and de-feminization which occurs before birth. Little research has been conducted to examine this hypothesis. One study that investigated hormonal factors found no difference between pedophiles and normal adults.
• Some evidence has suggested that brain pathology might be a factor, but the evidence is weak.
• A few speculative theories involve a chromosomal antigen which controls the development of sexuality and deviation through instinct and imprinting. However, no studies have specifically addressed the role of genetic factors in pedophilia.

Biological theories

• have little supporting evidence.
• fail to explain the age-specific attraction felt by pedophiles.
• do not explain the frequently observed fact that pedophiles "fall in love" with children. They cannot account for the fact that pedophiles exhibit a complex variety of feelings, perceptions, and behaviors, often including various kinds of relationships with children.
• assume that the human experience of interpersonal relationships can be reduced to biology, and that pedophilia--a theoretical idea--is a physical entity with a single biological cause.