Estimation of fear in two lines of the domestic chick: Correlations between various methods.

The assessment of fear is a controversial issue and low levels of correlation between different measures have been used to criticise the fear concept. The present study assessed fear levels in individual domestic chicks of each of two lines, flighty and docile, using four commonly employed methods of estimating fear. They were the hole-in-the-wall box, the open field, response to a bell and tonic immobility. On the basis of a wide variety of behavioural responses each chick was ranked for fearfulness in each of the four tests. The degrees of association or correlation between these ranking within lines were then calculated. The significant intra-individual correlations found in both lines provides some support for the use of these tests as methods of estimating fear, at least within the lines used. Differences in the degree or form of fear-responding between the lines are also discussed in terms of reactions to handling and to sudden auditory stimuli.