Differential fertility by intelligence: The role of birth planning

Abstract

In a sample of urban white U.S. women, an inverse relationship is demonstrated between fertility and IQ and is shown to come about because low‐IQ women have more unwanted births than high‐IQ women. The excess of unwanted births among low‐IQ women is caused by their elevated failure rate with temporary physician‐administered contraceptive methods. In order to control their fertility according to their own desires as well as do high‐IQ women, low‐IQ women require increased use of permanent birth control methods.