There are differing explanations for why ability could be a liability, all homing in on higher attentional control (through for instance high working memory capacity) biasing one towards highly conscious 'controlled processing', looking for perfect solutions when more automatic processing or loose heuristics do the job better, or at least protect you from falling into debilitating anxiety. If so, we could - we should - favour low-cognitive ability applicants for roles involving the kinds of tasks that show such effects. X and Y draw out three research areas that claim such effects, taking the position that the exceptional findings can be resolved by appraising the complexity of the tasks themselves.
First, 'pressure to perform' research asserts that when attempting difficult tasks, high cognitive ability individuals are more sensitive to pressures such as financial incentives or being observed, and their performance suffers accordingly. This is often construed as lower-ability individuals being more 'adaptable' to pressure. Beier and Oswalt firstly point out that in these studies the performance drop still leaves high-ability individuals doing better than their counterparts, just by a smaller margin than before. They go on to offer another account: under normal conditions, high-ability people do indeed tackle difficult tasks by bringing their attentional resources to bear, which pays off in superior performance. When pressure arises, which can indeed mess with highly conscious strategies, they rely more on the blunt, guessy, heuristic approach which low-ability people were using all along. Under this account, then, higher cognitive ability are *more* adaptable under pressure, changing up their strategies and still coming out top.
A study by DeCaro et al used a procedural learning paradigm where you must figure out the hidden rules to categorise images flashed on screen, varying in colour, shape, number and background. They showed that for simple rules high cognitive ability individuals learned faster, but the situation reversed when the rules were highly complex. Then, low-ability individuals are hypothesised to thrive by going with gut or employing kludgy strategies such as memorising individual successes rather than attempting to generalise to rules. But Beier and Oswalt suggest two problems concerning the goal of the task. The dependent measure of Task-Mastery was based on how long it took a participant to make a run of eight correct responses. But why not five? Or 15? A followup study showed that using 16-trial runs as your criteria, the ability liability disappeared. Perhaps more importantly, the goal was not explicit for participants. If it were, high-ability individuals might have exercised judgment as to whether to bother investing in solving the algorithm, or go for more imperfect tactics, as the reviews believe occurs in pressure to perform situations.
Finally, researchers investigating 'adaptive performance' have suggested that when learning a complex task, such as tank-battle simulations - a sudden change in the task demands (a massive terrain shift) is harder to stomach for those of higher cognitive ability, who experience a larger drop in performance at the point where we leave the familiar old world and bravely enter a new one. Again, this is marshalled as evidence of lack of flexibility due to commitment to one strategy.
In this particular study, the authors' analysis suggests that higher-ability people are not learning at a faster rate than their counterparts (presumably they begin with a higher capability, given that just as in the Pressure to Perform literature they do perform better overall than their counterparts). But through some simple modelling Beier and Oswalt demonstrate that this is hard to believe, as it suggests that in a complex situation with constantly changing demands - hundreds of brave new worlds - higher ability people would get worse and worse with respect to those with less ability, which is a radical claim. Instead, they suggest that the parallel learning rates are due to the analysis approach used, and that in truth the finding is more intuitive: higher ability means you learn a situation more quickly, and thus have more to lose at the moment where the conditions are altered.
This line of research line will continue, as we seek to better understand how performance is influenced by a range of interlocking factors. For now, Beier and Oswalt conclude that their review "is strongly aligned with one of the most consistent findings in over a century of psychological research: Cognitive ability exerts a main effect such that the smarter you are, the better you will perform on just about any complex task, all else being equal."
Beier, M., & Oswald, F. (2012). Is cognitive ability a liability? A critique and future research agenda on skilled performance. Journal of Experimental Psychology: Applied, 18 (4), 331-345 DOI: 10.1037/a0030869
Schmidt, F. L., & Hunter, J. E. (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124, 262–274.