lrnng&physiopsych

• Omnivorous species eat both plants & animals.
• A specialist species however is restricted to the niche in which they have evolved their particular adaption & may only be able to eat a few types of foods

Humans are less vunerable to reductions in the availability of a particular food source

• Less adaption in enzymes & other mechanisms to deal with problems specific to a particular food
• Risk of ingesting toxins that are spread across a wide range of potential foods
• Risk of nutritional imbalances bcos there are many potential foods with nutritive value but not complete nutrients

That young children can select an adequate diet with minimal social tuition

• Necessity (what is available & affordable)
• Instrumental reasons (dietary or religious requirements)
• Hedonics - Major factor (ingest what we like & reject what we dislike)

• We like sweet & salty tastes (correlated with calories in nature)
• We dislike bitter & sour tastes (correlated with toxins in nature)
• We ingest small amounts of novel foods (neophilia) & prefer familiar foods (neophobia)

• We rapidly come to like foods rich in energy or protein
• We learn to select foods that correct a nutritional imbalance or aid recovery from sickness
• We come to dislike foods prohibted by our culture
• We come to dislike foods whose ingestion was followed by malaise

That conditioned preferences can be established by pairing flavour with nutrtive infusions (rats drank more when flavour was paired with glucose than with water IG infusions)