Roskes, Sligte, Shalvi and De Dreu (2011) found that goalkeepers dive more to the right than to the left when they are behind in a penalty shootout than when they are tied or ahead. Roskes et al. (2011) argue this is the case because goalkeepers who are behind are more approach motivated than goalkeepers who are tied or ahead. The rightward bias occurs when people are approach motivated and under time pressure; like goalkeepers who are behind in a penalty shootout. Unfortunately Roskes et al. (2011) do not mention why only goalkeepers who are behind are approach motivated. There is also a methodological concern; the original data do not support the claim they make (see my earlier blog post). And this finding can have massive impact, because goalkeepers could train to overcome this bias and stop more penalties. For these reasons it is important to replicate this finding and see if the rightward bias is a real thing.
To do this in a confirmative way, we registered exactly what we were going to measure and which analysis we would perform (see an earlier blog post). Unfortunately we could not stick with our initial plan entirely, because the quality of some videos was extremely bad. The most important thing about the registration is that we should stick with our original analysis and that is still the case.
The analysis showed that; goalkeepers dived equally to the right and the left, when their team is ahead, X²(1, N=124) =2.613, p = 0.106. Goalkeepers dived equally to the right and the left, when their team is tied, X²(1, N=163) =3.245, p = 0.072. Goalkeepers dived equally to the left and the right, when their team is behind, X²(1, N=41) =.610, p = 0.435. This results show there is no rightward bias in goalkeepers.
Our replication study showed there is no rightward bias in the diving direction of goalkeepers when their team is behind. Our study also showed how important it is to pre-register the analysis you intend to do. When we would analyze all the penalties together instead of separately for behind, tied and ahead, we would find goalkeepers do dive more to the right, X²(1, N=329) =6.71, p = 0.01. We might end up concluding that we extended the original findings of Roskes, Sligte, Shalvi and De Dreu to apply for all goalkeepers. Instead of only the ones that are behind. Because conclusion dependent so heavily on the analysis you do, more researchers should pre-register their analysis. In that way it is sure the conclusions are confirmatory, nowadays it is often unclear whether a finding is confirmatory or exploratory. This study showed in a confirmatory way that the rightward bias does not exist in goalkeepers.
Roskes, M., Sligte, D., Shalvi, S., & De Dreu, C, K, W. (2011). The Right Side? Under Time Pressure, Approach Motivation Leads to Right-Oriented Bias Psychological Science, 22, 1403–1407.