To model phenotypic assortment, the approach described by Fulker (1982), and Neale et al. (1994) was applied which assumes spouse correlations arise through positive phenotypic assortative mating (Fig. 1b).
In general, the sex with the higher reproductive costs is expected to be more selective which is usually assumed to be the female [see [ 43] for a recent model explaining assortment by female mate choice].
Photos: The sweet smell of success: Clockwise from top: Emilio Pucci at work in 1959; a 1966 ad for Vivara perfume; the newly revamped Vivara; Marisa Berenson models an assortment of bags in 1965.
His sister, Lizzie Himmel, a photographer, recalls a charmed childhood: The night before Jimi Hendrix came to the studio to be photographed by her father, Paul Himmel, a documentary photographer, Ms. Himmel sneaked downstairs and modeled the assortment of fringed leather vests the musician intended to wear for the shoot.
The phenotypic assortment model was slightly preferred over the social homogamy model, suggesting that assortment for intelligence is mostly due to a selection of mates on similarity in intelligence.
Both assortment models caused a significant decrease in model fit, but the SH model fitted the data relatively worse than the PA model (according to χ difference test, Akaike's information criterion (AIC), Bayesian information criterion (BIC), and Deviance information criterion (DIC)).
A model assuming phenotypic assortment fitted the data better than a model assuming social homogamy.
Preference of the assortment model was based on maximum likelihood estimation.
Although helping often increases more rapidly with lowered relatedness in the gene-based model, positive kin assortment is still required.
In contrast, under the positive phenotypic assortment model mate selection is purely based on the phenotype of the spouses (i.e., similar general intelligence).
