Mike Murray wrote:
Being a serious chess player requires an equally serious time
commitment, time that *could* be spent on a profession or other
activities. Some people believe that the act of mastering chess has a
training effect that transfers to other activities. If this is true
(and I'm a wee bit skeptical about this), then the career time "lost"
to chess is offset by the resulting increase in mental power,
diligence, competitive spirit, etc., resulting from chess. But does
one get full value in other spheres for the time invested in chess? I
doubt it.

That is hitting the nail on the head, again, although it is a related
question instead of the main one. It is where I would claim that chess,
like many other brain-building activities, has a synergistic effect. So
instead of doubting it, I believe one does get full value, but the
proof is lacking... There are a few doctoral dissertations on this
topic that show positive effects, but we all know that only a large
scale study could even begin to provide the first building block of
actual "proof"....