Researchers from the University of Hertfordshire looked at the number and type of toys a group of under-seven-olds asked for in their letters to Father Christmas.
The children were then quizzed about their TV viewing habits - and their Christmas requests were compared with those of a group of Swedish six-year-olds, where advertising aimed at children is banned.
Dr Karen Pine, a research fellow in psychology, and her colleague Avril Nash, found that the British children asked for significantly more items than the Swedish children.
There was a direct correlation between the number of items asked for and the amount of TV watched. However, in the main, it was not the items advertised which the children requested.
Of the 175 children's products advertised during the research period, 152 were never requested. However, 80 per cent of adverts shown during the run-up to last Christmas were aimed at children. Significantly, children who watched more television on their own asked for the highest number of items and remembered the most brand names.
Children from three primary schools in Hrtfordshire and one nursery in Bedfordshire took part in the project.
"The more they watch, the more they want," said Dr Pine, who presented her findings to the conference yesterday.
"Although their recall of brand names at this age is pretty poor, the general effect is that it is making them a bit more materialistic.
"When you asked children what adverts are for, they think they are public information messages or that they are there to entertain you. It is not until eight years old that they understand that somebody is trying to sell you something."
Their findings suggested that those children who were watching a lot of television on their own were the most susceptible to advertising.
"The lone-viewing data suggests that, by watching TV with their child, a parent can lessen the impact of adverts, probably by helping the child develop a little healthy scepticism," said Dr Pine.
Because the children had not been aware they were taking part in a research project, using their letters to Father Christmas was seen as a very "naturalistic" method to look into the effects of TV advertising on children.
Although the Swedish children asked for fewer items, other cultural influences - apart from television - could not be ruled out.