It’s the voice in your head telling you yes, you should save that scrap of tinfoil, and no, it’s not okay to buy the really soft toilet paper. Your spending quirks and what they say about you.

It’s ten o’clock on Saturday morning, and I’m standing at the bathroom sink, saving money. In my left hand, I’m holding a nearly full bottle of hand lotion, in my right, a nearly empty one, with a pump that no longer reaches the lotion at the bottom. I’m attempting to pour the contents of the old into the new when it occurs to me that I’ll be standing here all weekend unless I find a way to position the bottles to drain on their own.

Fifteen minutes and a trip to the basement later, I’ve got it: I’ve fastened the necks of the bottles together with duct tape. Brilliant! Now I won’t waste a single drop. My husband walks by and doesn’t even pause; he just rolls his eyes. What he has silently communicated is, “I can’t believe how you’re wasting your time. That whole bottle cost two dollars and seventy-nine cents! So what if you end up throwing away eight cents’ worth?”

Okay, my Inner Cheapskate sometimes gets the upper hand. And when this happens, yes, ten cents really does matter. Forget the custom shelves I just ordered for the living room; it’s paying for the premium brand of frozen broccoli that I resent.

“We can justify the big stuff,” explains Jane Greer, Ph.D., a therapist in private practice in New York City. “It’s necessary. You need a car and a place to live. But when people spend on the little things, it makes them feel extravagant and self-indulgent. And that triggers guilt.”

The classic psychological explanation for my cheapskate behavior may be that I don’t think I’m worth spending money on. But with all due respect to the mental health community, I think there’s a little more to it than that. It’s not that I don’t splurge on myself: I spent $100 on makeup just last month. Yet I still have these, well, quirks.

And I know I’m not alone. Lots of women can’t throw away anything useful-even, or especially, if the usefulness is not readily apparent. I can’t get rid of a sheet of paper that’s been used on only one side; as a result, my 11- and 8-year-old sons already have enough drawing paper to hold them until colic get Likewise, Julie Packer of New York City buys fairly expensive socks for running, “but I wear them down until they fray in the washer and tangle with my bra straps,” she explains, “and it’s a major operation to untangle them.”

Blame the Puritan ethic for our tight-fisted–and often contradictory–spending habits, says Paul Schervish, Ph.D., a professor of sociology at Boston in College who studies what people buy and why. American wallets, he says, are often affected by conflicting desires–to show off our financial well-being (the $25,000 sport utility vehicle) while “maintaining the moral high ground of never having spent too much” (that not-so-soft Brand X toilet paper). That high-mindedness, he adds, can help us keep our greed in check–and our checks from bouncing.

Still, it’s sometimes hard to tell when you’re being sensible (getting your shoes resoled) and when you’re taking frugality too far (experimenting with personal uses for recycled tires). Here’s a clue: The Inner Cheapskate always thinks convenience is unimportant, and values her time at way below minimum wage. Jenni Green, of Salem, OR, for example, paid her hills in person until she realized she was making several extra trips–costing her time and gas money–to save $1.60 in postage.

Personally, I’m learning not to let my Inner Cheapskate run amok. There is, after all, my dignity to consider. I try hard to remember this when I find myself crouched in front of the grocery-store freezer, searching the sticky bottom shelf for the bargain brand of frozen orange juice–a full 32 cents cheaper than Tropicana.