What does it mean that mental representations guide behaviour and how has this been shown in research?

All information that humans take in through the sensory system: sight, hearing, smell, taste, and feeling, is processed. In the processing people often use pre-stored information in the memory. How people process information is closely related to the way they perceive and think about the world, which also is what leads to how they behave.

This is for example demonstrated in a study made by Darley and Gross 1983. It was a laboratory experiment where two groups of participants were shown a video of a girl playing in a poor respectively a wealthy environment. Then they all were shown the same video of the girl taking an intelligence test. After seeing this they were asked to judge the future of the girl. The results were that the participants that had seen the girl play in a poor environment all said that the girl would do worse than the participants that had seen her playing in a rich environment. The study demonstrated that people process information - the video of the girl playing in a poor respectively rich environment, and use it to guide their behavior: judging the future of the girl.