Using the temperamental trait “boldness” (or the “shy-bold continuum”) as an example, Wilson and colleagues (Wilson et al., 1994; Wilson, 1998) argued that, depending on the ecological circumstances, it might be favourable for an individual to facultatively express either a shy or a bold reaction pattern in the face of challenge (e.g., novelty, a predator, a conspecific, etc.).This was described as “domain specificity” or “phenotypic plasticity” of response, as opposed to “domain generality” or “phenotypic rigidity” (see also Réale et al., 2000; Sih et al., 2004a, b).In the present thesis, this twodimensional or “two-tier” model (see Koolhaas et al., 2007; Coppens et al., 2010) was proposed to explain the multivariate response pattern of calves to open field (OF) and novel object (NO) tests (chapter 3).
This might explain, for example, why the same animal is fearful of humans, but non-fearful of novel objects (e.g., Visser et al., 2003; Janczak et al., 2003a; Gibbons et al., 2009a), or aggressive and agitated towards conspecifics, but non-aggressive and non-agitated during manual restraint or handling (e.g., Mendl et al., 1998; Réale et al., 2000; D’Eath and Burn, 2002), etc.
The concept of coping style assumes that individuals may show alternative types of response patterns to the same challenge, e.g., either a passive or an active type of reaction (Koolhaas et al., 1997, 1999).
Importantly, passive coping by no means indicates that animals are “passive” in the sense that they do not respond.
If we accept the argument that some paradigms, or some behavioural or physiological measures recorded within the same paradigm, primarily reflect the level of responsiveness (e.g., fearfulness), and others mainly indicate the qualitative type of response (e.g., coping style), then by definition the resulting overall response pattern should be multidimensional if both types of paradigms are used, or both types of measures are recorded, in the same experiment (see Ramos and Mormède, 1998).
A more conceptual version of the two-dimensional model of responsiveness previously presented in chapter 3 is shown in Figure 7.1.