Ever wondered why you can successfully resist a big temptation over an extended period of time, only to then fall into some “smaller” sin which should have been much easier to reject? Dan Heath says the answer may have something to do with cookies and radishes.

Students come into a lab. It smells amazing—someone has just baked chocolate-chip cookies. On a table in front of them, there are two bowls. One has the fresh-baked cookies. The other has a bunch of radishes. Some of the students are asked to eat some cookies but no radishes. Others are told to eat radishes but no cookies, and while they sit there, nibbling on rabbit food, the researchers leave the room – which is intended to tempt them and is frankly kind of sadistic. But in the study none of the radish-eaters slipped – they showed admirable self-control. And meanwhile, it probably goes without saying that the people gorging on cookies didn’t experience much temptation.

Then, the two groups are asked to do a second, seemingly unrelated task—basically a kind of logic puzzle where they have to trace out a complicated geometric pattern without raising their pencil. Unbeknownst to them, the puzzle can’t be solved. The scientists are curious how long they’ll persist at a difficult task. So the cookie-eaters try again and again, for an average of 19 minutes, before they give up. But the radish-eaters—they only last an average of 8 minutes. What gives?

The answer may surprise you: They ran out of self-control. Psychologists have discovered that self-control is an exhaustible resource. And I don’t mean self-control only in the sense of turning down cookies or alcohol, I mean a broader sense of self-supervision—any time you’re paying close attention to your actions, like when you’re having a tough conversation or trying to stay focused on a paper you’re writing. This helps to explain why, after a long hard day at the office, we’re more likely to snap at our spouses or have one drink too many—we’ve depleted our self-control.

You can read the whole article or watch Dan Heath on video here. But here’s my takeaway from this article:

1. This fascinating research certainly helps to explain (but not excuse) some incidents in my own life.

2. When I’ve been especially disciplined and successful in self-denial, I am at my most vulnerable.

3. Self-control can only get me so far. I need the Holy Spirit if I am to last beyond 19 minutes (or in my case closer to 19 seconds). In fact, why not depend on the Holy Spirit from the first second?

4. I worship Jesus Christ even more, especially as I consider His unbreakable moral and spiritual strength during that lonely and unrelenting 40-day temptation in the wilderness. And the “secret” of his success? Jesus entered the wilderness “filled with the Holy Spirit” and returned “in the power of the Spirit into Galilee” (Luke 4:1, 14).