Does anybody really believe that humanity evolved with access to fatty deep sea fishes? The reason that the omega 3 & 5 free fatty acids of fish oil have beneficial effects is because they have almost exactly the same chemicals as are available on your father's face.
In fact there are more than seven hundred similar chemicals in the facial and oral oils that we pass to one another when we kiss each other. So which would you rather do, kiss or eat fish? If you rub the healthy adult male facial sebaceous skin surface lipids off onto chewing gum and just collect them for three days, you can give a big dose (just 150 mg, but a big dose as far as potent pheromones are concerned) and observe the effects: Crime stops. Drug Addiction stops.
There is a book about this on the web: Kisses pass epigenetic pheromones, mainly the facial skin surface lipids which contain more than 735 oddball chemicals that are strange in exactly the stereochemical ways that typify insect pheromones. The human appetite for kissing pheromones uses the same pathways as addiction, but without all the harsh side effects.
As you might expect, kissing of our father's faces is the most important for finding peace and love in life. Without enough paternal affection (i.e. kissing your dad's face to pick up enough of his facial skin surface lipid 'kissing pheromone'), you run high risks of criminal or drug-seeking appetites that may be difficult to control. If you kiss your mother too much without enough affection from your father during childhood, you run the risk of that kind of unmentionable ideation and behavior.
Happily, scientists have been able to reverse criminal, drug-seeking, and unmentionable behavior of all descriptions with a one-time, 150 mg dose of the paternal facial skin surface lipid taken by mouth. See: Nicholson B. Of Love KISSES PASS EPIGENETIC PHEROMONES IN THE PATHOGENESIS OF SOCIOPATHY, 'MENTAL ILLNESS' AND DISEASE The Cure for Crime. The Cure for Drug Addiction. It is available free on google and on Amazon.