"Confirmation Bias"

People tend to seek confirmation of their beliefs.

“Confirmation bias” is the psychological term defining this human behavior that is constantly looking for and interpreting given information based on existing beliefs, expectations, and hypotheses.

Internet search systems and social networks unveil this human feature.

http://psycnet.apa.org/?fa=main.doiLanding&doi=10.1037/1089-2680.2.2.175