[quote=@mdk]
Show me the gland which causes altruism.
[/quote]

If you are actually interested you can see variations in altruistic behavior with gene distributions of neuroreceptors like DRD4 in various areas of the brain. While it is a mistake, in my view, to ascribe complex behaviors like altruism to any single gene, it does demonstrate the type of chemical linkages which will probably make up an essentially chemical model. It is nearly always more complicated than a single gene of course, not even considering epigenetic factors, but the more we learn the more understandable chemical linkages we discover.