Fluid intelligence (basically ability to process new things quickly) falls with age while crystallized intelligence (basically knowledge/experience) continues t

Fluid intelligence (basically ability to process new things quickly) falls with age while crystallized intelligence (basically knowledge/experience) continues to improve, eg: http://examinedexistence.com//wp-content/uploads/2013/12/crystallized-fluid.jpg http://examinedexistence.com//wp-content/uploads/2013/12/cry... Depending on what your problem is you may want a younger person or an older one, or both.