Networks


That the structure of social networks is important to all species of social animals is a given. Also all social networks have rules which define the structure. Rule breakers threaten the status quo and are not usually encouraged and the effect of breaking the rules may result in the rule breaker complying with the majority. But if the number of rule breakers hits a particular threshold, what happens? Does the network change or does it disintegrate?

Hock and Fefferman of the State U of NJ have fired up their computer and carried out some simulations (1). Their virtual people were in groups of 50 and had to make friends. They could choose friends and then change two at each step in the simulation using one of two criteria. Their success in the group, i.e. becoming “popular,” was measured by their connectivity after 200 steps in the simulation.

The friend selection criteria, or The Rules, were either that the people were looking to be directly connected to the most popular individuals for one set of simulations, or that they were selecting friends who had the best connectivity for the other simulations, thereby becoming popular by having the most effective network.

Rule breakers ignored the criteria and dropped and befriended at random. The questions asked are firstly, how do the rule breakers affect their social (popularity) position? Secondly, how does the rule breaking effect the popularity structure of the network?

The answers are somewhat different depending on the type of network. If the network was based on everyone wanting a direct connection to the most popular, nothing much happened to anyone unless there was a large number of rule breakers and then the structure changed. So if the network relied on an alpha male that had to be worshipped, then the system would fall apart if enough network members said “To hell with that!”

For the networks where success depended on the best connectivity, breaking the rules by failing to try to connect with highly connected individuals didn’t hold those rule breakers back. By cutting across the normal routes, they could disrupt the success of others while improving their position if their numbers grew. But checks and balances (rewards/punishments) would be easier to build into the system to maintain the network structure.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026652


Catching A Win


Sitting in our armchairs, we are wise critics as we watch world-class athletes performing in their sports and shout our advice at the TV screen. But what if their sport is also our sport? Can we see so clearly why our performance isn’t anywhere near as good? Well, we don’t have as much time to practice and then we don’t have the optimal equipment, do we?

There is some evidence that that we may be able to raise our performance if we can borrow the big guy’s stuff. This is known in the business as positive contagion, but in the cold light of dawn, do we really believe it occurs? It’s time it was put to the test. Lee et al have done just that and published their findings in the current issue of the Public Library of Science (1).

They picked golf as their chosen sport and selected a group of undergrads who were about 19-years old. 38 were guys and 3 were women, all who claimed to be members of the golfing fraternity. They were asked to try putting on a training mat, but half of them were offered the identical putter to a successful PGA player (Ben Curtis) and were informed that it was actually his putter. The rest just had to accept the putter as a tool of the trade.

The results were amazing. The putters who thought that they were using the top professional’s putter sank more putts. Their average was 53%. The control group who thought that they were putting with a plain putter, puttered along with a mere 38%. It gets even better, though, when they were asked to estimate the size of the hole that they were aiming at. The lucky-putter group estimated that the hole was larger by about 10% than the control group.

So apparently positive contagion works. Even the task seems easier. That the big man is thought to have used the equipment produces a significant improvement. Sadly, there is one experiment missing. They should have also sneaked the actual master’s putter in and checked if there was real magic in addition to the perceived advantage that was only in their minds.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026016

Do Me A Flavor


The craving for strange flavor combinations of food is a well-known stereotype of one of the behaviors of pregnant women and is always good for a smile in a movie. However, flavors from foods are perhaps the most important factor in our ongoing choice of diet. We can work hard to focus on a healthy diet, but sooner or later we start to crave the monosodium glutamate enhanced flavor of some junk food or other.

It’s not even that a particular flavor is automatically universally liked that governs our craving, but just ones that we have learned from an early age. We may think that it was the free toy that got us started, but it probably goes back even further. How far? Back to the perinatal stage in some cases. What our moms were eating before and after we were born is part of our flavor heritage.

When we were weaned, our diet changed dramatically and very often for quite bland foods.  Many of us screamed, threw stuff about and got generally bent out of shape by the whole process.

Do animals have the same problems? Oostindjer et al from Wageningen U have had a look at pigs and fed some sows on a diet flavored with trans-anethol with others on a control diet (1).

Anethol gives a strong anise flavor. It is responsible for the flavor in absinthe and its solubility behavior produces the cloudy appearance when water is added. It also works well as a mosquito repellant which may have been good for the pigs. Note: no absinthe was drunk by the pigs.

Once the piglets were ready to become weaners, they were grouped in pens which had flavored food, just anise smelling air but normal food, or the control food and air. The piglets that had the most fun, playing and getting on with their pen-pals, were those who had the anise flavored air. Having flavor in the food didn’t do that much for them. Just the smell made them happy as Larry. Having just plain old, plain old food and air resulted in a manipulative bunch of squealers.

I guess the message that we can take away is that we need to choose our flavors early but wisely. Living with lots of garlic odor might be a hard choice just to get to happy mealtimes when weaning our kids.

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0025318

Cognitive Calisthenics


Answering e-mails and organizing meetings, lunches or other exciting events in the social calendar is the first task of the day after crawling out of bed to get a kettle filled and heating. I carry on happy in the knowledge that I’m exercising my amygdala and keeping its grey matter density up to snuff.

After that comes the attention to the social networks: Facebook, Linked-In and Google+, which have a little overlap, but not very much. Again the fleeting fingers on the keyboard do double duty and massage my amygdala as they scan through to see what people have been up to.

Of course, other parts of the brain are involved too. Kanai et al, in Proc. Roy. Soc. B, chose 125 post-grad students of U C London as lab rats for fMRI studies of their brain structure (1). Young post-grads are expected to have very active thumbs servicing large numbers of Facebook friends and so they should be good candidates to see what all this thumb activity was doing to their brains.

They would also have quite large circles of normal friends – ‘normal’ in this context means ones that they would go to parties and get drunk with, like post-grads have been doing for generations. Hence, they could all be expected to have good plump amygdalas. But what else would also be plumped up by their Facebook work instead of their notebook work?

Three other areas were seen to have benefitted from their diligence in increasing their social network size. The areas where their grey matter had been plumped up in proportion to their number of Facebook friends were the EC, the right STS, and the Left MTG (2). Sounds good, but what do these parts do?

The ER is active in organizing memory so when your number of Facebook friends gets into the hundreds, things need to be well ordered. It is also the first part to go if Alzheimer’s strikes. So we can see our fast moving thumbs as a good sign.

 The right STS is associated with our noticing what motion others are carrying out and processing what that means for us. The left MTG is implicated in our processing of word-meaning. As many comments are short and somewhat cryptic when posted on the ‘Walls’ of Facebook, it is not surprising that we are heavily exercising these parts of the brain which are implicated in social perception.

It would appear that our brain plasticity is well up to the challenges set by the excitement of wandering around reading the Walls in Facebook. A ‘ripped brain’ somehow doesn’t sound as desirable as ‘ripped abs’ though, does it?

    1. R. Kanai, B. Bahrami, R. Roylance and G. Rees, Proc. Roy. Soc. B (2011).              Doi: 10.1098.rspb.20-11.1959 
    2. EC – Entorhinal Cortex; right STS – right superior temporal sulcus; left MTG – left middle temporal gyrus.

Teen Choices


Once we get to 30+years old we look at teenagers as being both wilder and more likely to get into trouble than we were at that age. One of the problems is that by this time we have kids and are struggling with all the pitfalls that ‘society’ seems to be putting in their way.

 A genuinely disturbing trend shows up when we look at the rate of pregnancies for girls between 15 1nd 19 years old. The US has the highest rate which is about twice as high as the UK’s, the second highest. The rate is 7-times that of the Netherlands, a country that has a pretty liberal reputation.

This trend caught the eyes of Stranger–Hall and Hall of U of Georgia and so they dug into the meta-data available for the US (1). Most of the States have laws advocating the teaching of abstinence along with sex education in the schools. Some states have more general sex education than others. As a result, some states have comprehensive sex education with information about sexually transmitted diseases included. Some do not and push hard that abstinence is basically what students should know about.

The result shown by this study is that the pregnancy rate increases in proportion to the emphasis on abstinence only with less comprehensive information. It appears that the serpent is alive and well and is tempting the teens to nibble at the fruit of the tree and abstinence is a challenge.

The clear recommendation from this study is that comprehensive sex education with information on STDs is beneficial and that teen pregnancy rates fall  for groups with more information, as do the rates of infection of STDs. Clearly just nibbling at the fruit of the tree isn’t as good as serving up a whole hot apple pie and cream (bearing in mind that we are pretending that it’s an apple tree in the Eden of Innocence when it’s more likely to have been a fig tree).

  1. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0024658