Why do people have different opinions about an object when they are given different information about that object?

Question

I'm studying about perception in psychology. My teacher has an example.

In an experiment, the researcher gives two groups a photo of one person. To Group 1, researcher says "This is a scientist", group 1 usually reacts "He has a bright and intelligent face, great mind are shown on his eyes". To group 2, researcher says "This is a murder", group 2 usually reacts "He had a dangerous face, he seems angry all the time".

How do you explain that using perception in psychology? does that experiment truly exist? Is there any real similar experiment?

Someone tells me it's because of "Confirmation Bias". It's the tendency to search for, interpret, favor, and recall information in a way that confirms one's preexisting beliefs or hypotheses. I doubt it.

Answer 1

There is a tendency to want a named response. Such as 'confirmation bias' - a bit as if confirmation bias were a thing, like a computer processor. But it is not. It also may be useful to notice that nothing in the world can be perceived directly. The image of your teacher is put together in your brain based on your perception and past experiences; if you develop prosopagnosia you will not perceive the teacher's face any more. Even the surface of the table you touch is not perceived directly, appreciation of the rough wooden surface is the result of synthesis of perceptions and memories.

Therefore the photo of the person in your experiment is appreciated through your priors/givens and you will find what you are (unconsciously) looking for. You can call it a particular bias, however many of them have been described and they overlap. For example you could view this one as perceptual priming or you could consider this an anchoring effect.

• Snyder, J. S., Schwiedrzik, C. M., Vitela, A. D., & Melloni, L. (2015). How previous experience shapes perception in different sensory modalities. Frontiers in Human Neuroscience, 9. https://doi.org/10.3389/fnhum.2015.00594
• Damasio, A. (2004). Looking for Spinoza (New Ed edition). London: Vintage.
• Lyons, J. (2017). Epistemological Problems of Perception. In E. N. Zalta (Ed.), The Stanford Encyclopedia of Philosophy (Spring 2017). Metaphysics Research Lab, Stanford University. Retrieved from https://plato.stanford.edu/archives/spr2017/entries/perception-episprob/
• Kahneman, D. (2011). Thinking, Fast and Slow. Farrar, Straus and Giroux.
• Priming (psychology). (2018, March 17). In Wikipedia. Retrieved from https://en.wikipedia.org/w/index.php?title=Priming_(psychology)&oldid=830901864