The sexy son hypothesis is closely related to the good genes assumption and the Fisherian runaway selection process. Like good genes, the sexy son hypothesis assumes the existence of indirect genetic benefits that are able to compensate for any inferior direct reproductive success (i.e., fewer offspring).
The attractive son hypothesis shares close ties with the good genes assumption and the Fisherian runaway selection mechanism. Like good genes, the attractive son hypothesis suggests that indirect genetic advantages can compensate for reduced direct reproductive success (fewer offspring).