Pair-bonding influences affective state in a monogamous fish species.

In humans, affective states are a key component in pair-bonding, particularly in the early stage of a relationship. Pairing with a high-quality partner elicits positive affective states which, in turn, validate and reinforce the mate choice. Affective states thus strongly affect pair stability and future reproductive success.

Hormonal and fitness consequences of behavioral assortative mating in the convict cichlid (Amatitlania siquia).

In monogamous species, partner compatibility is a key factor influencing pairing and reproductive success. In pairs with biparental care, studies have mostly focused on behavioral compatibility because it is likely to encourage the coordination of parental care within pairs, leading to a better reproductive success. Behavior modulation, throughout the breeding season and as a function of the social context, is under the regulatory feedback control of endocrine mechanisms.

Mismatched partners that achieve postpairing behavioral similarity improve their reproductive success.

Behavioral similarity between partners is likely to promote within-pair compatibility and to result in better reproductive success. Therefore, individuals are expected to choose a partner that is alike in behavioral type. However, mate searching is very costly and does not guarantee finding a matching partner.