science

Whitten effect

Whitten effect is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Whitten effect rather than just read about it. In short: The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population. Social signals, or social stimuli, have an effect on reproduction in all mammals.

Key takeaways

Whitten effect belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Whitten effect to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Whitten effect from memory before moving on to harder problems.

Reference excerpt

The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population. Social signals, or social stimuli, have an effect on reproduction in all mammals. For certain female mice, the pheromones contained in the urine of male mice can be such stimuli, inducing synchronous estrus. When the pheromones contained in the urine of male mice stimulate synchronous estrus in a population of female mice, it is known as the Whitten effect. This is a phenomenon observed by Wesley K. Whitten (1956, 1966, 1968), whereby male mouse pheromone-laden urine synchronizes the estrus cycle "among unisexually grouped females," and is an example of male-to-female pheromonal effects in mice, similar to the Bruce effect. The Whitten effect occurs when a group of female mice are exposed to the urine produced by a male mouse. The male’s urine contains certain volatile, or airborne, pheromones that affect the hormonal processes of the females that control their reproductive status. A sexually mature and viable male must produce the urine, as the pheromones that produce the Whitten effect are dependent on male sex hormones such as testosterone. The female mice do not require direct contact with the male’s urine to produce the Whitten effect, as the pheromone contained in the urine is airborne and therefore is taken up by the females through their olfactory system. The reproductive cycle of female mice in isolation is approximately 4 to 5 days, and the reproductive cycles of grouped females are often longer and more irregular. However, when grouped female mice are exposed to the pheromones contained in a male’s urine, the Whitten effect occurs, and the majority of the female mice will enter a new estrus cycle by the third day of exposure. However, there is little evidence for a similarly functioning vomeronasal, or olfactory, system (thought to be the sensory organ that initiates the Bruce, Vandenbergh, and Whitten effects) in humans. These differences, in putative stimulus and neural pathway (as well as species observed), stringently distinguishes the Whitten and McClintock effect, as the latter does not posit a role for male pheromones.

See also Bruce effect Lee–Boot effect McClintock effect Vandenbergh effect

References

Sources Whitten, W.K. (July 1956). "Modification of the oestrous cycle of the mouse by external stimuli associated with the male". Journal of Endocrinology. 13 (4): 399–404. doi:10.1677/joe.0.0130399. ISSN 0022-0795. PMID 13345955. Journal code: 0375363 Whitten, WK (1957-12-21). "Effect of exteroceptive factors on the oestrous cycle of mice". Nature. 180 (4599): 1436. Bibcode:1957Natur.180.1436W. doi:10.1038/1801436a0. PMID 13493564. S2CID 4285117. Gangrade, BK; Dominic, CJ (August 1984). "Studies of the male-originating pheromones involved in the Whitten effect and Bruce effect in mice". Biology of Reproduction. 31 (1). Biology of Reproduction: 89–96. doi:10.1095/biolreprod31.1.89. PMID 6540606. Whitten, W.K. (1966). "Pheromones and mammalian reproduction". Advanced Reproductive Physiology (1): 155–177. Whitten, WK; Bronson, FH; Greenstein, JA (1968-08-09). "Estrus-inducing pheromone of male mice: transport by movement of air". Science. 161 (3841): 584–5. Bibcode:1968Sci...161..584W. doi:10.1126/science.161.3841.584. PMID 5690897. S2CID 12402072.

Worked examples

Example 1 — a first encounter with Whitten effect

Start with the simplest possible case. Write down what Whitten effect claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Whitten effect before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Whitten effect ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Whitten effect

In research: Whitten effect appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Whitten effect in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Whitten effect is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ethology, Menstrual cycle, so understanding it makes those chapters shorter.
In everyday life: Look for Whitten effect outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Whitten effect in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Whitten effect means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Whitten effect out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Whitten effect in simple terms?

The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population. Social signals, or social stimuli, have an effect on reproduction in all mammals.

Why does Whitten effect matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Whitten effect?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Whitten effect.