The perfect giver of Christmas presents rarely gives money, always wraps gifts and draws attention to the "ritual sacrifice" of shopping they endured in order to find them, say psychologists. The less-than-perfect are unaware that gift blunders can ruin relationships, and cause family rows.
Ritual gift-giving at Christmas is a risky activity, subject to a web of rules, unwritten and often unconscious, say Carole Burgoyne and Stephen Lea, psychologists at Exeter University. "Gifts are never merely gifts," they say in this month's The Psychologist. Rules determine "with a surprising degree of precision what presents are appropriate".
"To violate these rules, to give too little, or indeed to give too much, can be insulting." Presents must "in some cases balance, and at other times be unequal. Inequalities of age, gender, wealth, power or social status may all be reflected."
If you want to insult, try giving money, which is only appropriate if it comes from a higher status to a lower status person in the same family. Money implies a "lack of effort on the part of the giver, as if the effort of shopping was required as some kind of ritual sacrifice," say the psychologists.
To please, you must emphasise the efforts you went to to buy the present - "it is through the process of 'appropriation' that mere commodities are converted into gifts".
If you are male, remember that men give more valuable gifts than women, and women are used to receiving more gifts than men are. Women must remember that they tend to give more presents than men and that they do most of the selection and shopping for gifts.
When you open your present, lie and say: "You shouldn't have" or "I was not expecting anything". We all like to pretend that gift-giving at Christmas is voluntary, say the psychologists. But research shows that if you do not produce a gift when you were expected to you can damage a relationship.
If by this time you are regretting that this year you resorted to 50 pence pieces stuck on card then wrap them up well: wrapping emphasises that it is giving that is important not what is inside.