A Generalizability Analysis of Subjective Personality Assessments in the Stumptail Macaque and the Zebra Finch

Abstract

Psychometric findings are reported from two studies concerning the construct validity, temporal stability, and interrater reliability of the latent common factors underlying subjective assessments by human raters of personality traits in two nonhuman animal species: (a) the Stumptail macaque (Maraca arctoides), a cercopithecine monkey; and (b) the Zebra finch (Poephila guttata), an estrildid songbird. Because most theories of animal personality have historically implied that certain personality constructs should be relatively universal across taxa, parallel analyses of similar data are reported for two phylogenetically distant species of subject using the same psychometric methods. Each of the samples was drawn from a socially-housed colony of the same species: that of macaques consisted of 5 mature adult fem ales and 8 of their adult offspring and that of finches consisted of 5 adult individuals. A modified version of the 1978 Stevenson-Hinde and Zunz (SHZ) list of personality items was applied to the macaques at various times during the eight years from 1980-1988 and to the finches during 1992. This study also used the three SHZ scales - Confident, Excitable, and Sociable - originally derived from principal components. Generalizability analyses were used to assess the construct validity, temporal stability, and interrater reliability of the hypothesized factors. Both Stumptail macaques and Zebra finches manifest measurable personality factors that are highly valid across multiple items, stable across multiple years, and reliable across multiple raters. The same model fits both species, as predicted by theory. The construct validity of the factors is slightly higher for the finches than for the macaques, although the interrater reliability is somewhat lower. This study illustrates how generalizability analysis can be used to test prespecified confirmatory factor models when the number of individual subjects is quite small.

Personality assessment in the Great Apes: Comparing ecologically valid behavior measures, behavior ratings, and adjective ratings

“…These three factors could be replicated in the same species (StevensonHinde et al, 1980a), as well as in stump-tailed macaques (Macaca arctoides; Figueredo, Cox, & Rhine, 1995), pig-tailed macaques (Macaca nemestrina; Caine, Earle, & Reite, 1983), and chimpanzees (Pan troglodytes; Murray, 1998). Other studies --in gorillas (Gorilla gorilla; Gold & Maple, 1994) and again in rhesus macaques (Bolig, Price, O'Neill, & Suomi, 1992;Capitanio, 1999;Capitanio & Widaman, 2005) --yielded four factors including two or all three factors shown in the other studies.…”

“…Buirski, Plutchik, & Kellerman, 1978;Figueredo et al, 1995;Gold & Maple, 1994;King & Figueredo, 1997;King et al, 2005;Pederson et al, 2005;StevensonHinde & Zunz, 1978, Stevenson-Hinde et al, 1980a, or both (Weiss, King, & Perkins, 2006). The definitions' implicit connotations may however mask those of the adjectives.…”

Individual Differences and Animal Personality

“…Also, this review of animal studies of personality will concentrate on primates due to the vastly more developed literature in this biological order compared to others. It should be said however that attributions of personality have been made to a number of nonprimate species including dogs (Canis familiaris; Jones & Gosling, 2005), birds (Zebra finch (Poephilia guttata); Figueredo, Cox, & Rhine, 1995), and even squid (Euprymna tasmanica; Sinn & Moltschaniwskyj, 2005) and the octopus (Octopus rubescens; Mather & Anderson, 1993). Taken in sum, studies of personality in nonhuman animals constitute an impressively broad and developed literature.…”

The Experimenting Society

“…Within comparative psychology, temperament and traits have been observed and examined across multiple taxa, including domestic dogs (Canis lupus familiaris; Fratkin, Sinn, Patall, & Gosling, 2013), Rhesus macaques (Macaca mulatta; Stevenson-Hinde & Zunz, 1978;1980), and Stumptail macaques (Macaca arctoides; Figueredo, Cox, & Rhine, 1995). For the dogs, Fratkin and colleagues (2013) performed a meta-analysis on personality stability, and those results revealed a moderate overall trait stability effect size in canines (r = .43).…”

“…Among the rhesus monkeys, trait stability was sampled and assessed three times over a four-year interval (Stevenson-Hinde & Zunz, 1978) by means of three separate exploratory principal component analyses, producing highly convergent results and moderate temporal correlations among the consecutive time points for the traits (Spearman's ρ = .69 -.92, depending on the trait factor). For Stumptail macaques, trait stability was sampled and assessed six times over an eight-year interval by means of a single Generalizability Theory (GT) analysis of the traits previously identified for Rhesus macaques by Stevenson-Hinde & Zunz, producing high GT coefficients (E 2 rel = .682 -.772, depending on the initial assumptions made in two alternative GT models; Figueredo, Cox, & Rhine, 1995). The findings broadly reveal that animal temperament and traits remain constant over time (see Gosling, 2001 for a review).…”