Word for a cycle where the cause is made worse by the effect [closed]

What is the word for a cycle where the cause is made worse by the effect? A very simple example is a decline in fish leads to a decline in coral reef health which then leads to a further decline in fish and so on.

Solution 1:

A vicious cycle is the term you want.

2. a chain of events in which the response to one difficulty creates a new problem that aggravates the original difficulty

^[M-W]

EDIT: The term is also known, as others have pointed out, as vicious circle. I prefer cycle because it better connotes the iterative nature of the process.

Here are some usage examples from vocabulary.com:

Science:

As Arctic permafrost thaws, it unleashes a vicious cycle—the unfrozen soil releases its carbon reserves that intensify climate change, in turn accelerating the thaw.

^{Scientific American Feb 9, 2018}

Technology:

This reversed a vicious cycle of previous generations that saw high data costs leading to sparse use of data-heavy features, and sparse use of data-heavy features being used to justify high data costs.

^{The Guardian Jun 29, 2017}

Business:

A rising dollar increases the value of dollar debt in local currencies, making repayment more difficult and depressing currencies further in a vicious cycle.

^{New York Times Jul 13, 2018}

Sports:

Observers now describe a vicious cycle in which fewer at-large bids for leagues and teams lead to fewer resources and less exposure, leading to declines in recruiting and performance, leading to fewer at-large bids.

^{New York Times Mar 15, 2017}

Solution 2:

It's feedback, or more specifically positive feedback:

the enhancement or amplification of an effect by its own influence on the process that gives rise to it.

GOOG

"Positive" here is not a judgement on the result as good or bad. It's a statement that the cause is magnified, and often yields unstable behavior. Negative feedback usually diminishes the effect.

the diminution or counteraction of an effect by its own influence on the process giving rise to it

GOOG

Solution 3:

Not a single word, but a downward spiral or (less commonly) a death spiral. Wiktionary says a downward spiral is, "A series of thoughts or actions which feeds back into itself, causing a situation to become progressively worse."

Solution 4:

"Snowball effect" might also work for you. Where as things progress, the results build upon themselves for good or bad.

It comes from the idea of a small snowball rolling down a snow-covered hill, and the snow sticks to the snowball causing it to continually increase in size as it rolls down the hill.

Solution 5:

The correct term for this is a 'positive feedback cycle' or a postive feedback loop.

It sounds unintuitive as the word 'positive' is mostly associated with improvement. However strictly speaking it is correct as here we are saying that the gap between the the current state and the ideal state INCREASES (i.e. by a positive amount) after applying the change, so things are worse off than when we started. A negative feedback loop would be one where the effect is diminished after each cycle and moves closer to the ideal state.