Does a hill look less steep when you are with a friend? In one experiment, university students stood at the bottom of a hill and guessed how steep it was. Students with a friend said the hill was less steep than students who were alone.

But other scientists had a question. Maybe the students guessed what the researchers wanted and changed their answers. Scientists are still discussing this.

A 2008 study by researchers at the University of Virginia and elsewhere suggested that friends can change how we see the world. University students stood at the bottom of a hill and estimated its slope. Those standing with a friend judged the hill to be less steep than those standing alone, and the effect was stronger when they had known the friend longer. Even imagining a supportive person had a similar effect.

However, similar experiments faced criticism. In one, people wearing heavy backpacks judged hills as steeper, but another team found this mostly happened among participants who guessed the purpose of the study. When they were given a believable reason for the backpack, the effect disappeared.

It is comforting to think that friends literally make our challenges look smaller. In 2008, researchers at the University of Virginia and elsewhere reported that students standing at the foot of a hill with a friend estimated its slant as gentler than students standing alone, and that longer friendships were linked to larger effects. Merely imagining a supportive person while viewing the hill had a similar influence. The authors interpreted this as evidence that available resources shape perception itself.

A related line of work found that wearing a heavy backpack made hills appear steeper, but a later team questioned this. When they asked participants why they thought they were wearing a backpack, the effect was concentrated among those who had guessed the hypothesis, and providing a plausible cover story eliminated it. This pattern points to experimental demand, where participants adjust their answers to fit what they believe researchers expect.

In 2016, researchers at Yale reviewed many claims that thoughts and feelings alter perception and concluded that none provided convincing evidence, identifying pitfalls such as demand and confusing perception with judgment. Social support may still make a climb feel easier, but whether it changes what we literally see is unresolved.