I suppose the first thing for the guys, Mary, would be their ability to pump must be measured.....iron, that is...then, were they grumpy while doing so, happy, oblivious with a glazed look in their eyes? And, of course music would have to be factored in...we could do controlled experiments like with the houseplants and music....look he has ahem grown and is leaning more towards the sunshine as a result of our playing "Afternoon Delight" nonstop for a week! BUT, has it made him any nicer???

I don't think the personality thing would work as well for change with guys...they can't help it...sometimes the little guy just has a mind of his own.