Many thanks for your interest in Prof Wiseman's online experiments exploring the psychology of Christmas. The studies have now been completed, and the results are described below. These studies were carried out in collaboration with The Daily Telegraph.

There is more about Prof. Wiseman's work here, and an opportunity to take part in his new study exploring the psychology of Love At First Sight here.

By Richard Wiseman
A few weeks ago, I invited readers of this newspaper to participate in the first experiments to unwrap the science behind two great British traditions - the telling of terrible cracker jokes and the sending of Christmas cards.
Thousands of people responded and the results shed light on issues that have puzzled scientists for decades What are the best and worst Christmas cracker jokes? Do more expensive crackers contain better jokes? What does your choice of Christmas card reveal about your personality?
A few days before the study, I bought crackers that ranged in price from a few pence to several pounds, carefully extracted the jokes and placed them on our experimental website. Participants were asked to read each joke and indicate whether they found it funny or unfunny.
The verdict of more than 2,000 people proves what many have suspected for years - Christmas cracker jokes are simply not funny. A massive 65% of participants waded through the gags without once ticking the 'funny' box, and even the best jokes didn't raise much of a giggle. Only 12% of people thought the top-rated joke - 'What do you call a penguin in the Sahara desert? Lost' - was funny. Second place, went to that old football classic: 'What do you call a woman who stands between two goal posts? Annette'.
And if you thought those were bad, wait until you see what came towards the bottom of the league table. Just 3% of people thought that the second to last entry was funny - 'What kind of tree do fingers grow on? A palm tree' - and less than 1% of people saw the funny side of the worst joke of all: 'What is the vampire's favourite song? Fangs for the memory'.
Because our unfortunate experimental subjects didn't know whether the jokes had come from cheap or expensive crackers, we were able to conduct a controlled test of the relationship between mirth and cost. The results were clear - paying more for your crackers will not result in an increased level of laughter around the dinner table. Or, as we psychologists like to say, there was no correlation between expenditure and positive affect.
The top rated 'penguin' and 'Annette' jokes came from crackers costing just 41p and 25p respectively. In contrast, the low rated 'palm tree' and 'vampire' joke were found in crackers costing over £3.00. The cheap jokes are the best.
So why has this strange tradition survived the test of time? The experiment offers some tantalizing clues. Before rating the jokes, everyone was asked to rate their joke-telling ability. The data suggests that Britain is awash with poor comedians, with less than 10% of respondents describing themselves as being very good at telling jokes.
Everyone was then asked whether they liked telling jokes in general, and cracker jokes in particular. When it came to jokes in general, some predictable differences emerged - 95% of the highly-skilled joke-tellers enjoyed relating jokes, compared to just 10% of bad joke-tellers. But when it came to cracker jokes, the pattern was reversed. Now, only 36% of skilled joke-tellers said they enjoyed telling cracker jokes, compared to 42% of bad joke-tellers. So, the bad joke-tellers much prefer telling cracker jokes. Perhaps they like the fact that cracker jokes are written down, as this reduces the chances of them forgetting the all-important punchline. Or perhaps they like them because they can blame the resulting groans on their poor material, rather than their lack of comedic ability. Either way, the tradition has survived because bad joke-tellers vastly outnumber good joke-tellers, and bad joke-tellers relish the seasonal chore of delivering terrible cracker jokes.

League table of Christmas cracker jokes
TOP

What do you call a penguin in the Sahara desert? Lost.
What do you call a woman who stands between two goal posts? Annette
On which side do chickens have most feathers? On the outside.
What do you call a train loaded with toffee? A chew chew train.
What's furry and minty? A polo bear.
What's big, grey and wear glass slippers? Cinderelephant.
Why are ghosts so bad at lying? You can see right through them.
How do snails keep their shells shiny? They use snail varnish.
What must you know to be an auctioneer? Lots.
Did you hear about the man who bought a paper shop? It blew away.
What kind of tree do fingers grow on? A palm tree.
What is the vampire's favourite song? Fangs for the memory.

What can Christmas cards tell us about personality? In a second online experiment, I decided to investigate. Participants completed a standard personality test, studied six types of Christmas card - modern, traditional, religious, humorous, cute, and abstract - and indicated the type of card that they would prefer to send.
I discovered a strong relationship between personality and card type. For example, people who are drawn to modern designs tend to be extroverted, easily upset, and highly unconventional. In contrast, those who prefer religious cards are more emotionally stable, sympathetic, and well organised. Six very different personality profiles emerged, with many of the findings supporting existing theories linking personality and brain functioning.
Extroverts were drawn to the relatively striking modern designs and humorous cards, whilst introverts preferred more sedate-looking traditional cards. Why should this be the case?
Research suggests that each person's brain has a different pre-set level of arousal, much like a TV has a pre-set volume when you switch it on. Introverts have a high pre-set level of arousal, and, as a result, tend to avoid situations that further arouse their already stimulated brains. Because of this they prefer a quiet evening in with a good book to a night out on the town, and are drawn to Christmas cards showing relaxing traditional scenes.
The opposite is true of extroverts. Their brains have a much lower pre-set level of arousal, and thus have a need for the type of continuous stimulation that results from being with other people, along with bright, modern Christmas card designs or those that make them laugh.
Social scientists have long been fascinated by the way in which social networks bond society together. The sending of Christmas cards could be used to help identify the types of people that are highly connected and those that are more socially isolated. For example, we discovered that women send just over twice as many christmas cards as men, suggesting that women might be much better connected than men. However, as with any experimental data, it is important to be open to other ways of looking at the situation.
Men who didn't send cards scored low on a personality dimension known as 'agreeableness' - a measure of the degree to which people are critical of others - and thus might not send cards because they care less about making potential recipients feel good. There again, the data also revealed that women who sent a large number of cards were highly conventional, suggesting that their excessive card sending might be the result of a need to comply with societal norms, rather than genuine concern for others. The data also helped explain why men and women often fail to impress one another with their choice of card. They have very different tastes, with, for example, 30% of women liking modern cards versus only 16% of men, and only 14% of women liking humorous cards compared to 32% of men.
Both of the experiments have revealed that complex science lurks beneath seemingly simple of traditions. How bad cracker jokes have survived the test of time because they appeal to the vast number of poor comedians across the land. How paying more for your crackers is no guarantee of increased mirth. How your choice of Christmas card reveals a significant glimpse of your personality. These exciting findings have motivated me to continue researching the topic. Next, for example, year I hope to place Santa Claus on the couch and explore the childhood experiences that cause him to feel the need to spend one night of the year rewarding good behaviour around the world.

What do your Christmas cards reveal about your personality?
Modern: Extroverted and enthusiastic about life, although somewhat anxious and easily upset, with a tendency to be more creative and unconventional than most.

Humorous: Outgoing and emotionally secure, but with a distinct lack of warmth and sympathy for others.

Traditional: People who prefer reading a good book to a night out on the town, with a tendency to experience extremes of emotions, and follow the rules.

Abstract: Tendency to be disorganised and spontaneous, highly strung, and a low need to surround themselves with others.

Cute: Sympathetic, calm and open to new experiences, and with a tendency to prefer one's own company to others.

Religious: Emotionally stable, sympathetic to the needs of others, and well organised.