Bégin J, Beaugrand J P, Zayan R
Unité d'Ethométrie, Département de Psychologie, Université du Québec à Montréal, C.P. 8888, suc. A, Montréal, Québec, H3C 3P8, Canada.
Faculté de Psychologie, Université de Louvain, B-1348 Louvain-la-Neuve, Belgium.
Behav Processes. 1996 Jun;36(3):219-26. doi: 10.1016/0376-6357(95)00031-3.
Individuals with a previous experience of dominance are likely to be dominants in further encounters. To test this effect, individuals with a previous experience of dominance are used for the experiments. One way to obtain such individuals is to let opponents 'self-select': encounters between pairs of more or less equivalent opponents are staged and one selects ex post facto the dominant and subordinate from the ensuing conflict. This paper formally shows that the selection of dominant and subordinate animals modifies the dominance probability functions of the two corresponding sub-samples of animals. As a result, the propensity of previous winners to win again and of previous losers to repeat their loss can be attributed to this artefact rather than to prior social experience. This result has serious methodological implications. When one relies solely on selection to obtain winners and losers, equiprobability is no longer the appropriate null hypothesis against which prior social experience effects have to be tested. To clearly demonstrate the effect of dominance experience, one must show that prior winners defeat neutral opponents in at least two-thirds of all cases; reciprocally, to show that prior subordinate experience plays a role, prior losers must win in less than one-third of all fights against neutral opponents; finally, to conclude that a combined effect of the two kinds of prior experience is in operation, one must obtain that prior winners defeat prior losers in more than 83% of all planned conflicts. The present result does not imply that experience effects are not at work when the selection procedure is used, but that the procedure used to show their effects is inadequate because effects of experience on a subsequent encounter are confounded with those introduced by statistical selection.
有过主导经历的个体在后续相遇中很可能成为主导者。为了测试这种效应，实验采用了有过主导经历的个体。获得这类个体的一种方法是让对手“自我选择”：安排实力大致相当的对手两两对决，然后从事后发生的冲突中选出主导者和从属者。本文正式表明，主导动物和从属动物的选择改变了这两个相应动物子样本的主导概率函数。因此，先前的获胜者再次获胜以及先前的失败者再次失败的倾向可归因于这种人为因素，而非先前的社会经验。这一结果具有严重的方法学意义。当仅依靠选择来获得赢家和输家时，等概率不再是检验先前社会经验效应时合适的零假设。为了清楚地证明主导经验的效应，必须表明先前的赢家在所有情况中至少三分之二的情况下击败中立对手；相应地，为了表明先前的从属经验起作用，先前的输家在与中立对手的所有战斗中获胜的比例必须低于三分之一；最后，为了得出两种先前经验的综合效应在起作用的结论，必须得出先前的赢家在所有计划的冲突中超过83%的情况下击败先前的输家。目前的结果并不意味着在使用选择程序时经验效应不起作用，而是表明用于展示其效应的程序不充分，因为经验对后续相遇的影响与统计选择引入的影响相互混淆。
