Herding Bubbles


Often we make our choices the easy way. By that, I mean we see what other people are doing and follow their lead if the outcomes look good. It’s easier than digging deeply into the background pros and cons and, of course, we don’t really have the time to do that. If something looks really good, we want a piece of the action, and now, before it’s too late.

This is the stuff of what economic bubbles are made of, and participation in the rush is known by the people watchers as herding, although flocking seems to be a better descriptor.

During the building of a bubble, some do very well, but, as usual, there will be tears when the ephemeral structure bursts. As we philosophize over our beers, we all agree that we won’t do that again, but of course we do. After all, next time a bubble may not really be a bubble, it may be a trend to a sustainable state.

So what should we do when we see a herd building a bubble? Ask a physicist of course. Eugene Stanley and his fellow physicists took on the question, experimented, modeled and reported out in the current Proceedings of the National Academy of Science (1).

The experiment seemed simple. Their students acted as lab rats and had to choose one of two rooms to receive an equal share of whatever resource that room held. The room resources were kept secret. The sequence was repeated 30 times with participants being able to change rooms each time. Physicists like to be thorough, so the experiment was repeated with the relative resource in the rooms being biased more heavily with each experiment. They also added a cyber herd to the mix in various levels of herd size.

Cutting to the chase, following the herd is a bad idea when the resources are even. The herd leads to ruin with very small potatoes for everyone. As the resource in one area moves to very heavily outweigh that in the other, everyone in the herd gets a reasonable share and a stable equilibrium is achieved. As the size of the sneaky cyber herd grows, the transition from ruin to happy equilibrium isn’t achieved until a higher resource imbalance is in effect.

 At first sight this result seems somewhat comforting as if there is a really good thing going, more of us can join in and the bubble doesn’t have to burst. So can we embrace this as good news? Well, think globally. Look at the huge discrepancy in resources between the developed and undeveloped world. Where is the stable equilibrium as the herd moves to the high resource region?

  1. www.pnas.org/cgi/doi/10.1073/pnas.1105239108

All That Glisters – Indeed!



The price of rhinoceros horn has risen in recent years as rhino have had more and more protection. It’s a little ironic that the very part of their anatomy that has evolved for their protection is now the biggest source of the threat to their survival.

Their horns sell for about $100k per kg in the market places of eastern Asia, which becomes a tempting price to poachers with guns. It is not just the rhinos who are running around that are at risk of a nose clipping. Those stuffed and in museums are also under threat.

The museum raids aren’t new, though. I can recall the rhino in the Bristol, UK, museum that was out in the open and small kids would surreptitiously take a ride on its back. It had a horn that was apparently wearing away steadily over a long period. Somebody was quietly scraping away at it and rushing off for a Friday night special.

I visited it one day and found it wearing a plastic bag on its head. It then went on vacation and returned to reside in a large glass cabinet. The museum guys told me that its horn had become fragile from the demand and it was replaced. The one on the beast that had been so popular had actually been a fake and was made of plaster. I guess the placebo effect is live and well in that city.

The horny horn raiders are getting bolder. The BBC reports that they smashed down the Tring Museum’s front doors to grab two horns off stuffed rhinos (1). These were large weighty horns that would have been worth about a third of a million dollars if they hadn’t been fakes made of polyester resin.

The police are now searching for a couple of very disappointed guys whose actions certainly cast a pall over last week end in Tring and probably many week ends to come!

  1. http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-14693144



Comforting Words


Whether we are children or adults, if we are having a bad time we all respond to comforting words from a friend, spouse, parent or even a kindly passer-by. Often “good advice” isn’t what’s needed, but just the soothing sounds of sympathy. “There, there, don’t cry” doesn’t sound very helpful to a child with a cut knee. However, it usually works better than a detailed description of how we are going to clean it up and what might happen if it’s neglected, let alone what complications should be looked for in the future.

There are some situations in which we can’t be there in person, but the cell phone is now becoming almost universal, so we can elicit some soothing sympathetic words to comfort us that way. But what about instant messaging or texting? Can that do the job?

Seltzer et al of the U of Wisconsin-Madison set out to study exactly that and they have a pre-print that is flashing around in cyber-space as we speak (1). In their set of experiments, the ‘lab rats’ were young girls who were stressed out somewhat so the level of cortisol in their saliva was nicely elevated. Some were allowed to talk to their Moms, some over the phone and some in the flesh, whilst others were allowed to instant message and some, the valiant control group, just had to tough it out.

Talking to Mom, phone or in person, dropped cortisol levels and produced oxytocin, a hormone that induces calmness and decreases fear. Instant messaging did nothing like that, and their cortisol levels stayed as high as those who were just trying to get over it. The conclusion was that it is the sound of the familiar voice that helps and not the words.

However, the familiar may be especially potent, but I’m sure that sympathetic noises will work well even from an unfamiliar source. Maybe we should write a smart-phone app that will come out with a random variety of sympathetic phrases with a soft comforting voice speaking them. Then we can listen to a random selection to calm us down in stressful situations. Music helps, but the right voice might be better.

  1. doi:10.1016/j.evolhumbehav.2011.05.004

Sniffing It Out


Chemical recognition is an extremely important facility for most species. Of course, we enjoy smelling the flowers, freshly baked bread or our morning coffee, but sensing chemical messengers can be critical to survival, not just for what we call “higher animals,” but to our friends who live closer to the ground than we do. Papers in the current issue of Animal Behaviour have a couple of interesting examples.

Some experiments with leafcutter ants showed that they recognize leaves that are distasteful to the individuals enslaved on their fungal farms (1).  The experiments involved offering choices in the laboratory for leaves and odors of good or bad leaves to the foraging ants. The ants avoided anything that they had learned had a smell indicating unsuitability. However, they were much more positive about things if they were allowed to fondle the leaf parts. So they are a little more wily than we might think.

The second paper deals with the dating problems of snails in the mangrove swamps (2). The first problem that the snails have is a very complicated three-dimensional habitat to work in. Their second problem is that the population density is low and of course they don’t have the luxury of things like the internet (or do they?)

In the mating season in the mangroves, a male snail will show great diligence in following female snail trails. Outside the mating season they are much more blasé and wander casually along, but once in the mating season, there is a sense of urgency and our molluscular friends are almost galloping along the trails deep in the mangroves. Indeed, time and tide wait for no gastropod!


  1. N.Saverschek and F.Roces, Anim. Behav., 82, 453, (2011).
  2. T.P.T.Ng, M.S.Davis, R.Stafford, and G.A.Williams, Anim. Behav., 82, 459, (2011).

It's Tough At The Top


At the top of the food chain sit predators like us. But we’re not keen on competition when it comes to securing our food supply. The same is true of other predators and a common solution is to eat your way out of the problem. It is always good to have a theoretical hook to hang the observed behavior on, though.

There is even a handy dandy term for eating your fellow predators. It is termed intraguild predation. The current theory hooks used by the predatory bird cognoscenti are that the predators are trying to remove competitors, they are feeling pressure on their food supply and the one that is of interest today is that they are simply trying to remove predators so that in future they can go about their normal business and not come back to find the bones of their babies scattered to the four winds.

Lourenço et al in the current issue of Behavioral Ecology and Sociobiology tried to check the theories out with a set of raptors. There was sufficient food, so we can put food stress on the back burner for special occasions. They arranged realistic, but stuffed, eagle owls (predator/competitor) and a stuffed tawny owl (competitor) out by their nests.

Nobody cared about the tawnies but the eagle owls were severely harassed, so we are left with eat your predator before he/she eats you. This is clearly a case of super mob rule. We see crows mobbing buzzards and the like, but it must be more satisfying to feed juicy tidbits of someone who was trying to eat you to your brood. It sounds like the plot line of many of our movies!

  1. http://www.springerlink.com/content/78q11qv543138l53/