A study by Dr William H. Frey II, a biochemist at the St Paul-Ramsey Medical Centre in Minnesota, found that there is an important chemical difference between emotional or stress-related tears and those simply caused by physical irritants – such as when cutting onions.

They found that emotional tears contained more of the protein-based hormones prolactin, adrenocorticotropic hormone, and leucine enkephalin (a natural painkiller), all of which are produced by our body when under stress.

Ultimately we are striving for balance, to feel strong and confident, yet emotional and caring.

When we cry, perhaps our body is trying to find balance. If women have higher levels of Prolactin, then they would be prone to crying more often than men. Since Estrogen breaks down Dopamines, this would potentially lead to the hormonal imbalance women get during menstruation and pre-menstruation. 

This also has some interesting stuff on being in love and falling in love:

The unpalatable truth is that falling in love is, in some ways, indistinguishable from a severe pathology. Behavior changes are reminiscent of psychosis and, biochemically speaking, passionate love closely imitates substance abuse. Appearing in the BBC series Body Hits on December 4, 2002 Dr. John Marsden, the head of the British National Addiction Center, said that love is addictive, akin to cocaine and speed. Sex is a "booby trap", intended to bind the partners long enough to bond.

The BBC summed it up succinctly and sensationally: "Events occurring in the brain when we are in love have similarities with mental illness".
Falling in love involves the enhanced secretion of b-Phenylethylamine (PEA, or the "love chemical") in the first 2 to 4 years of the relationship. (Note from Erik: I have heard other studies that show PEA lasts for 6 months to 3 years in a new relationship)
This natural drug creates a euphoric high and helps obscure the failings and shortcomings of the potential mate. Such oblivion - perceiving only the spouse's good sides while discarding their bad ones - is pathology akin to the primitive psychological defense mechanism known as "splitting".
The activity of a host of neurotransmitters - such as Dopamine, Norepinephrine, and Serotonin - is heightened (or in the case of Serotonin, lowered) in both paramours. Yet, such irregularities are also associated with Obsessive-Compulsive Disorder (OCD) and depression.”
samvak.tripod.com/lovepathology.html

Chocolate has very high levels of PEA, but it is broken down in the stomach by Monoamine Oxidase B (MAO-B). If one were to consume a MAO-B inhibitor such as Deprenyl (which I will talk about later), chocolate would become psychoactive. 

Very interesting. I think I'm going to pay more attention to this stuff now that I am very aware of my emotions and how these are influenced by chemical substances natural or not. This stuff is fascinating to me now that I've felt how significant these things can affect me emotionally.