The Guardian has been reporting on the UK Parliamentary inquiry into homeopathy: catch a blow-by-blow account of the proceedings, or listen to a brief audio report, or read resident skeptic Ben Goldacre's column, in which he talks particularly about the placebo effect, and also the rather less-well-known nocebo effect.

This is the aspect that really interests me in all this: the placebo effect. It's fascinating, isn't it?, how tangled and entwined mind & body are. Wired had a great article about this a few months ago. Silberman writes about the difficulties drug companies are having getting new drugs to "beat placebo", and makes a comment that really stays with me, about how the placebo effect has been seen as:

"a problem for drug developers to overcome, rather than a phenomenon that could guide doctors toward a better understanding of the healing process and how to drive it most effectively".

No, I don't think homeopathy works even better than placebo -- but the point is, placebo works really well! And nocebo notwithstanding, it has much fewer side-effects.

A mouse study has confirmed that the immune system and the nervous system are linked through mast cells, which are an important part of the immune system but reside in the brain. This fact was known, and recent research has implicated mast cells in several stress and anxiety related behaviors, but this new study is the first to manipulate the mast cells and observe direct behavioral consequences. Asthma and food allergies, as well as other stressful conditions, affect levels of mast cells. The finding is another nail in the coffin of the idea that these two complex systems (the mind and the body, as it were) operate independently.

Did you catch the report a week or two ago about how you become more trusting of a stranger when your hands are warm? The experimenter, in the sneaky way psychologists sometimes behave, had an innocent assistant get each subject to hold a cup of hot coffee or a cup of iced coffee while the assistant wrote down their details, prior to judging the personality of an imaginary person they read about. Those who had held the hot coffee judged the person more positively than those who held the iced drink. The experimenter then followed the study up with another in which subjects were asked to rate the effectiveness of either a hot or cold compress pad, and then given their choice of reward: a gift for a friend, or for themselves. And yes, those who were pre-chilled were more likely to be selfish than those pre-warmed.

The study is an amusing reminder of the subconscious influences constantly acting on our behavior, but more than that, it points to the strong connection between the physical and the mental worlds, the body and the mind.

And a British study involving 1760 National Lottery winners and non-winners has found -- unsurprisingly but it's nice to have it quantified! -- that happiness is related to the number and quality of friends you have. Those with 5 friends or fewer only had a 40% chance of being happy, compared to having more than 10 friends, which gives you 55-56% chance of happiness. But quality counts! In Manchester and Birmingham, although the number of friends was below average, they were closer to them, and so happiness levels was higher. Whereas in Liverpool, though number of friends was above average, they were less close, and people weren't as happy. So there you go: nurture your friendships.