Repeatability and Heritability of Behavioural Types in a Social Cichlid

Table 1

Categorical Principal Component results for the behavioural testing, for each observer separately (in brackets the year(s) when the tests were conducted). The variance accounted for is represented by Cronbach’s alpha, and the Eigenvalue is given (% explained variance in brackets). In each case a single factor score was extracted, and used to characterize the behavioural type of the focal individuals on a testing day (one test series), used for the repeatability analyses. Scores were then averaged per individual for the heritability analyses (scores from two to six test series averaged). Tests used for Categorical Principal Component extraction: B = boldness, A = aggression, E = exploration.

	n test series	Tests used per series	Cronbach’s alpha	Eigenvalue
R. Schürch (2005-2006)	216	B, A, E	0.91	4.95 (61.9%)
S. Rothenberger (2007)	1042^a	B, A, E	0.94	6.65 (60.5%)
E. Bochud/S. Keller/L. Lasut (2008)	64	B, A, E	0.94	6.93 (63.0%)
M. Zöttl (2010)	288^b	A	0.85	2.30 (76.7%)
N. Chervet (2010)	1412	B, A	0.90	3.53 (70.4%)
D. Heg (2010)	1268^c	B, A	0.89	3.49 (69.7%)

^aIncludes 72 individuals that were subjected to an additional test series following the procedure of Schürch and Heg [39] in the 400-litre tank, analysed separately with CatPCA: Cronbach’s alpha = 0.93, Eigenvalue = 6.48 (58.9%).
^bIncludes 64 individuals for which also the boldness test was conducted, analysed separately with CatPCA: Cronbach’s alpha = 0.92, Eigenvalue = 3.75 (75.0%).
^cIncludes 8 test series were only aggressiveness was scored and analysed separately with CatPCA Cronbach’s alpha = 0.86, Eigenvalue = 2.36 (78.6%).