We’ve all heard about one behavioral or scientific effect or another, but perhaps we’re not sure we’re getting the name right, or even that we mean the one we think we do when we name it. Here are the labels of the most ubiquitous of effects and the thesis or the scientific principle underlying each one.
1. Bambi effect: Animals widely perceived as visually appealing will be given more consideration or sympathy than those deemed less attractive. (A rare additional connotation refers to homosexual men who engage in heterosexual behavior.)
2. Butterfly effect: A seemingly inconsequential event or incident can have momentous consequences.
3. Domino effect: Each in a series of events or incidents causes the subsequent phenomena.
4. Doppler effect: A wave’s frequency changes in relation to the relative position of the source or the observer.
5. Greenhouse effect: Heat emanating from a planetary surface will be absorbed and redistributed by atmospheric gases back to the surface or into the atmosphere, resulting in an increase in temperature.
6. Halo effect: The more attractive or appealing a person or other entity is, the more favorably they will be evaluated or the more sympathetically they will be treated.
7. Hawthorne effect: People being observed as part of a study will perform better or otherwise as expected simply because they know they are being studied.
8. Hundredth-monkey effect: A thought or behavior is widely and suddenly distributed through a group once a critical number of members of that group are exposed to the thought or behavior. (This theory is basically valid, but the claim of instantaneous transmission has been discredited.)
9. Mozart effect: Listening to music composed by Mozart temporarily improves performance on mental tasks. (This theory has been distorted to suggest that doing so makes the listener smarter; furthermore, additional studies have concluded that the specific composer or music genre, or whether one listens specifically to music at all, is irrelevant; experiencing anything one enjoys may improve performance.)
10. Placebo effect: Patients given secretly ineffectual or simulated treatment will perceive that their condition has improved, or that it will improve, because they believe the treatment has benefited or will benefit them.
11. Pygmalion effect: The more that is expected of people, the better they will perform.
12. Ripple effect: A single incident or occurrence may have consequences and ramifications beyond the scope of the original phenomenon.
13. Snowball effect: See “ripple effect.”
14. Streisand effect: Attempts to censor or conceal information lead to increased publicity.
15. Trickle-down effect: A consumer item may initially be affordable only for the affluent, but its price will likely decrease until people of more modest means can afford it (at which time it often becomes less attractive to wealthier people).