Four researchers at the University of Kansas (Phoenix, Goy, Gerall, and Young) performed in 1959 a break-through series of experiments on guinea pigs. Earlier work had shown that when male hormones are administered to pregnant female guinea pigs, the female offspring are anatomically masculinized - born with penises and scrotums. And some experiments had shown that when female guinea pigs are spayed and later given male hormones they display only a limited amount of malelike sexual behaviour. Phoenix et al combined the two types of experiments. Pregnant female guinea pigs were given androgens. The ovaries of the masculinized female pups were removed after birth and at maturity androgens were administered. The females behaved much like males. Brecher has termed this the Phoenix-Goy-Young effect.