Seven and up: individual differences in male voice fundamental frequency emerge before puberty and remain stable throughout adulthood

Voice pitch (the perceptual correlate of fundamental frequency, F 0) varies considerably even among individuals of the same sex and age, communicating a host of socially and evolutionarily relevant information. However, due to the almost exclusive utilization of cross-sectional designs in previous studies, it remains unknown whether these individual differences in voice pitch emerge before, during or after sexual maturation, and whether voice pitch remains stable into adulthood. Here, we measured the F 0 parameters of men who were recorded once every 7 years from age 7 to 56 as they participated in the British television documentary Up Series . Linear mixed models revealed significant effects of age on all F 0 parameters, wherein F 0 mean, minimum, maximum and the standard deviation of F 0 showed sharp pubertal decreases between age 7 and 21, yet remained remarkably stable after age 28. Critically, men's pre-pubertal F 0 at age 7 strongly predicted their F 0 at every subsequent adult age, explaining up to 64% of the variance in post-pubertal F 0. This finding suggests that between-individual differences in voice pitch that are known to play an important role in men's reproductive success are in fact largely determined by age 7, and may therefore be linked to prenatal and/or pre-pubertal androgen exposure.