A few years ago, my partner Elizabeth and I were walking in the woods just outside Los Angeles with our friend Olivia. After a while, Olivia realized that we were walking through poison oak. She immediately panicked. She was terrified that she’d have an allergic reaction.

To be honest, embarrassing as it sounds, even though I was in my thirties at the time I didn’t know what poison oak was, so I just shrugged my shoulders and walked on in the firm belief that the little green plants wouldn’t cause me any harm. Elizabeth told me she visualized herself protected.

By the next day, Olivia was covered in an itchy rash and Elizabeth and I were fine. That’s when I googled poison oak and poison ivy. Later, when researching the placebo effect for one of my other books, I came across a poison ivy study that made me smile. In the study, a group of volunteers who were known to be allergic to poison ivy were blindfolded and had their arms rubbed with a leaf. They were told that it was poison ivy and came out in a rash as a result. But the thing is, their arms were actually rubbed with a maple leaf. The belief itself was enough to stimulate a histamine reaction.

Another group of volunteers was told that their arms were being rubbed with a maple leaf, but it really was poison ivy this time. But they didn’t come out in a rash at all, even though they were all allergic to poison ivy. Their belief had overpowered their normal allergic reaction. Of course, I’m not saying that poison ivy doesn’t cause an allergic reaction – we know that it does. What I am suggesting is that the mind is able to overrule it.

The mind has far more ability to overpower the body’s programming than most people think. I have heard many people say that the reason they are easily stressed is genetic – their mother or father was highly strung so they can’t help it. It may be that they have inherited a genetic or epigenetic tendency to get stressed easily, but this doesn’t mean that they are destined to be stressed for life. A regular practice of yoga or meditation is usually enough to calm them down, even under exactly the same conditions in which they were stressed before. Harvard University research on meditation demonstrated that it impacted 1,561 genes in people who had never meditated before, activating 874 genes and deactivating 687.13 That’s some effect!

So, there are genetic currents of destiny – some that are inherited as normal from our parents, and others that are a consequence of their experiences in life. But our choices in life can overrule many of these effects. Yes, the river has a current, but our boat doesn’t always need to flow with it.