We’ve been sold on the idea of the power of positive thinking. From affirmations to optimism, if you want to succeed you must always look on the bright side.

But happy talk hasn’t always been so mainstream. When Norman Vincent Peale released his iconic book The Power of Positive Thinking in 1952, it was considered controversial. Several mental health experts came out against Peale’s work, calling him a con man and a fraud because of his frequent use of unnamed experts and testimonials.

Over the years, many of the naysayers went away or even joined his campaign (search Amazon for books on “positive thinking” and more than 37,000 titles pop up.) But the pendulum may be swinging the other way; books and studies are surfacing that question our relentless pursuit of happiness.

Here are five examples that suggest “bad” thoughts can have good results:

In her book Rethinking Positive Thinking, Gabriele Oettingen reveals that “a cheery disposition and good attitude can zap the motivation needed to mobilize and strategize… dreaming isn’t doing.”

“The current literature has pushed us to embrace this idea of positive thinking so much that we shun anything negative, and obstacles by nature are a negative thing,” she told The Atlantic in an article called “Optimism Is the Enemy of Action.” “So, we tend not to consider negative concepts or ideas and instead focus only on the positive, which our research shows isn’t actually very helpful at all.”

Oettingen says predicting obstacles is an important part of getting things done, but the key is not to dwell on them. “You want to integrate the obstacles into images of the desired future and then develop a plan that will help you circumvent or address the anticipated hurdles,” she said.