Age does have quite a few effects on performance (talking generally, there are always exceptions), e.g.
- long term memory recall for events;
- working memory performance when information load is high;
- accuracy of geometric and numerical reasoning;
- speed of numerical checking;
- knowledge and skill learning;
- attention capacity - divided attention and attention switching;
- speed of physical actions;
- skill learning;
- vigilance;
- visuo-spatial abilities;
- sleep loss;
- deterioration various aspects of visual function;
- deterioration in hearing; and
- acute health problems and incapacitation.
Some of these though can be improved with practice. While people may have a preference for certain tasks, and be naturally better at them, learning and practice can lead to improvement even in basic abilities. Also, skills relevant to controlling are found to different degrees in different people - so some (e.g. introverts [a generalisation]) might be better at vigilance tasks while others (e.g. extroverts) are better at handling emergencies for instance.
The following show little or no effect of aging:
- long-term memory for meaning;
- recognition (as opposed to recall); and
- automatic processes.
As you can see this does back up NATS general argument on safety grounds. The trouble with this is that there may be some exceptions to the general findings on age-related performance. It's those exceptions that cause the equity problems. To me, some age cut off is a common-sense measure that applies to only a minority of safety-critical jobs, and society needs to decide whether the compromise is acceptable for those roles, e.g. ATCOs, pilots, security screeners. Older controllers on the job currently have, as has been pointed out, the benefit of experience and so are working more at the levels of skills and rules rather than first principles.
The only way to go from here is to review aptitude tests to ensure that they are sensitive enough for factors that vary with age and are critical to ATC.
(As you can probably tell I'm a psychologist/ergonomist not a controller...
hello by the way!)
Last edited by HigherSights; 2nd Mar 2009 at 04:10.