The 5-a-Day Yellow Glow!

Your daily fruit and veg intake discernibly dictates the colour of your face, new research has shown...

Scientists at the University of St Andrews in Scotland began by asking 35 students to complete questionnaires logging their average daily intake of fruit and vegetables. These individuals, the data show, consumed a modestly healthy 3.41 fruit and vegetable portions per day.

Next, at three and six week time-points, the students' faces and other skin areas were imaged, the colours analysed and the results compared with the diet records.

Changes in fruit and vegetable intake during the study period, the St Andrews team found, were reflected in skin colour changes in the participants. Specifically, changes were seen in colours corresponding to the carotenoid antioxidants with which vegetables and fruits are richly endowed.

But were these changes perceptible to a person, or merely to a sensitive camera? To find out, Ross Whitehead, the lead author on the study which is published this week in the journal PLoS One, showed a second group of volunteers pairs of images prepared from four faces.

These had been manipulated to add increasing amounts of yellow colouration to the skin over a series of 22 otherwise identical images of the same face. This colour difference would have corresponded to a variation in intake of 5.55 daily portions of fruits and vegetables.

The study participants were asked to rate pairs of images of the same face as more or less healthy. Initially they were shown faces at each end of the 22-face spectrum; if they chose correctly, faces progressively nearer to one another on the colour spectrum were presented.

The subjects could discriminate a colour difference equivalent to consuming 1.89 more, or fewer, portions of fruit and veg per day.

This ties in with what has already been observed in other human studies: people rate yellower faces as more healthy and given free rein to digitally manipulate photos of faces, most people add extra yellow, mimicking the effect of extra betacarotene, the orange chemical in carrots.

The results also resonate with what goes on in the natural world. Dietary antioxidants alter animal colours and this can be used by potential partners as a measure of an individual's health and likely mating prowess. Individuals with a good diet, healthy lifestyle and antioxidants to spare can afford to spend some on making their skins look a nice colour! Humans, it seems, are no different.

So, rather than a fake tan and a nose job, the way to pull, it appears, is instead to reach for your banana and a healthy helping of nuts...

How you type a word could change the way you emotionally respond to it, and words typed with mainly the right hand seem to make people happier.  In fact, the layout of letters on a keyboard may even be shaping the way we use language.

The qwerty keyboard, named after the first 6 letters on the first row, was invented in 1868, and designed to keep commonly used letters apart so as to avoid the clashing and jamming that was possible with mechanical typewriters.  Although we no longer rely on the same mechanical processes to type, the keyboard layout has remained the same and is now ubiquitous.

Writing in the journal Psychonomic Bulletin & Review, Kyle Jasmin & Daniel Casasanto devised a set of experiments to test people's emotional response to certain words.  Previous research has shown the performing motor actions, such as typing, in a fluid way leads to positive feelings, so if typing is more fluent with one hand than the other, it could lead to a bias in emotion towards words typed with that hand.

To test this, volunteers were asked to rate how positive or negative they feel about a sample of around 150 words.  The experiment was done in three languages - English, Spanish and Dutch, with native speakers for each language, and a second test included newer words and internet acronyms such as LOL.

The results showed that words with more letters from the right hand side of a qwerty keyboard produced a significantly more positive emotional response - regardless of language and the volunteer's handedness.  Furthermore, the effect was even more pronounced in modern acronyms and words created since the invention of the qwerty keyboard.

To further test this idea, Jasmin and Casasanto wanted to know if keyboard bias would allow them to predict how positive people would find made up words, known as pseudowords, which have no inherent meaning that may alter emotional response.  Again, words with a right-hand bias were deemed to be significantly more pleasing.

The authors conclude that there truly is a bias towards feeling good about words typed with the right hand, and argue that this could be because the layout of the qwerty keyboard provides the right hand with an easier job.  They also suggest that this could have an impact on marketing, saying:"People responsible for naming new products, brands, and companies might do well to consider the potential advantages of consulting their keyboards and choosing the "right" name."