(evolutionary theory) The hypothesis, in evolutionary biology, that a female animal's optimal choice among potential mates is a male whose genes will produce male offspring with the best chance of reproductive success, irrespective of the mate's capacity as a caregiver or any other direct benefits he can offer.

The hypothesis that the evolution of life required an improbable combination of astrophysical and geological events and circumstances, and for this reason complex extraterrestrial life is a very improbable phenomenon and likely to be extremely rare.

(linguistics) The principle that the structure of a language affects its speakers' worldview or cognition.

(economics) The idea that the prices generated by a financial market represent the best possible estimate of any investment’s value.

Alternative spelling of trickle-down hypothesis

A form of cognitive bias by which people believe that someone's actions are inherently inclined to bring morally fair and fitting consequences upon them, with good deeds rewarded and bad deeds punished.

(biology, psychology) The hypothesis that women's taste in men, and subconscious thoughts and behaviors, change throughout the menstrual cycle.

(economics) The idea that policies benefiting the wealthy shall ultimately benefit everybody else.

A conjecture that expects that all spacetime singularities are enclosed within event horizons.

(economics) A theory attempting to describe how agents spread consumption over their lifetimes, supposing that a person's consumption at a point in time is determined not just by their current income but also by their expected income in future years, which is seen as the driver of change.