Behaviours and Psychometric Testing

One of the objectives of psychometric testing has been to predict performance based upon psychological characteristics. Two major categories of psychometric instruments are:-

•  tests of intelligence ;and
•  personality.

Both of these have a long history of predicting behavioural outcomes.

Intelligence tests, for example, were originally used to identify learning disability among school children while personality tests were geared primarily toward the prediction of dysfunctional behaviour. Following their broader adoption during the two world wars, these techniques gained prominence as tools for assessing performance ability and facilitating job placement.

While psychometric testing and performance prediction have evolved considerably over the past 100 years, their value is often underappreciated. This article highlights a lesson from this broad field – that research on performance prediction has taught us the importance of (a) choosing the right people and (b) using the right tools to do so.

Price’s Law & The Right People

Most people would agree that in a competitive environment, the most qualified individual should be chosen for a given position. However, there are many obstacles to the real-world implementation of this meritocratic ideal. One such obstacle is the fact that people tend to underestimate the massive performance and productivity differences that exist between individuals.

A powerful illustration of this is codified in ‘Price’s Law’ which describes the unequal distribution of productivity in any creative domain. According to this formula:

the square root of the number of people working in field produce 50 percent of the total output.

For example, if there were 100 scientists working on a problem, the 10 most productive would produce the same amount of material as the remaining 90.

This concentration of creative work becomes even more pronounced at the highest ends of the productivity distribution. The most prolific individuals within a domain generate disproportionately larger shares of the total output.

Although Price’s Law was originally used to describe the unequal distribution of creative output, its message extends to non-creative work as well.

Studies of performance variability indicate that as the work domain becomes more complex, the variability in performance across individuals becomes larger.

While selecting the best people is an important goal in itself, a parallel goal of no less importance is screening out undesirable candidates. The consequences of choosing the wrong people are substantial as they lead to increased turnover rates, recruitment costs and training costs, along with lost productivity and decreases in morale. The high costs associated with replacing poorly performing individuals make it all the more important to identify and select the best performers in the first place.

The complete version of this article first appeared in The Psychologist September 2009 and this extratc has been taken from our Development Academy. For more information visit our website relating to personal development and selection assessments.