The new iPhone. A Blu-ray movie with deleted scenes. A simple firmware update. We’re collectively obsessed with the new and improved, and according to researchers at the University of York, there’s a good reason: New features can create a placebo effect for an experience feeling more fun and immersive.

Researchers had a group of 21 people play the popular game Don’t Starve, which drops you onto a randomly generated map, and forces you to survive by gathering various resources, crafting tools, and avoiding monsters.

Everyone played the game for a set period of time. Then, for a second round, half of them were told that, instead of a “standard AI,” the game would feature an “adaptive AI” that would tweak the level based upon a player’s experience. Of the placebo group, some said the game was harder. Others, easier. But everyone believed it. And the explanations could get pretty involved.

“I think the adaptive AI makes objects in the game appear more often when I need them. It reduces the time of exploring the map which makes the game more enjoyable,” said one player. Another claimed, “Avoiding insect nests seemed to result in an abundance of them in newly explored areas. The first night a spider walked into my circle of light then ran away as I approached, as a result of me no following it out of my campfire area, the tactic seemed to change and on the second night a group of 3 spiders just charged up to my character”.

However, whether or not they found the game harder, across the board, researchers found that adaptive AI players were more immersed in the game world, expending more cognitive effort to play. And on top of that, they rated the adaptive AI version of the game more entertaining.

Researchers concluded two important takeaways:

1. “The mere expectation of a difference can be sufficient to change the experience.”

2. “Given the prevalence of sequels in the game industry, we must take any claims for advances in the underlying technology with a pinch of salt. Players may have an improved experience over earlier versions of the game simply because they expect it.”