If, as theists and supernaturalists contend, our "mind" is actually a supernatural, non-material entity, then it's hard to see how or why our physical condition or the biochemical state of our bodies would have any impact on how the mind operates. On the other hand, if as naturalists and scientists argue, the mind is a purely physical phenomenon based on our material, physical brain, then our physical condition and state of our body should be expected to have a variety of impacts on how our minds operate.

It's hardly surprising that the latter is exactly what scientific research finds, and recent research has demonstrated that our blood-sugar level can have a measurable impact on our decision-making abilities. If our blood-sugar level is too low we normally don't feel like making any serious decisions, and that's a good thing because we are less likely to use our reason in whatever decision we are asked to make. Instead we use intuition — not a process that is guaranteed to lead to wrong decisions, but frankly I'd rather rely on reason.

Psychologists have known for a long time that having a decoy option in a decision-making task draws people to choose a reasonable option that is similar to the decoy. Dr Masicampo and Dr Baumeister suspected that students who had been asked to work hard during the video and then been given a drink without any sugar in it would be more likely to rely on intuition when making this decision than those from the other three groups. And that is what happened; 64% of them were swayed by the decoy. Those who had either not had to exert mental energy during the showing of the video or had been given glucose in their lemonade, used reason in their decision-making task and were less likely to be swayed by the decoy.

It is not clear why intuition is independent of glucose. It could be that humans inherited a default nervous system from other mammals that was similar to intuition, and that could make snap decisions about whether to fight or flee regardless of how much glucose was in the body.

Source: The Economist

If we don't want to make decisions when our blood-sugar levels are too low, where is that counter-drive coming from? It's almost as if our brain is trying to protect us (meaning itself) from the bad decisions it is likely to make under such circumstances. Athletes are trained to pay attention to what their bodies are "telling" them in order to know when not to push themselves past physical limits where they might injure themselves. Maybe we should also pay more attention to what our brains are telling us; unfortunately, sinced our physical brains are us, it's tough to sort out what signals are what.

Regardless, the next time Jehovah's Witnesses of Mormons knock on your door and you're thinking about debating them, maybe you should give them some lemonade to drink first. Not only will it demonstrate good hospitality, but it might make for a far more productive discussion in the end. It certainly won't make discussion and debate any worse, will it?