The Formidability Heuristic
Predict women's physical mate preferences by asking which body would win a fight
- Difficulty
- Easy
- Time to result
- ~days to results
- Steps
- 4
- Confidence
- 62%
Macken Murphy's predictive rule for women's bodily mate preferences is to ask, of two male physiques, which looks like it would win a fight. Whichever reads as more formidable is usually preferred. The mechanism is evolutionary: in ancestral environments a mate who could disincentivise harassment of a woman and her children conferred survival benefits, so women's psychology tracks bodily predictors of fighting ability, strong veiny hands, big arms, broad shoulders, height, and a body that is lean but not shredded. This explains why women preferred the softer 'before' physique in viral transformations: heavyweight fighters are lean but not stage-ready, because being shredded is not optimised for combat. Extreme optimisation also cues effortful mating-effort, which reads as a worse long-term partner, so the fight-winner rule outperforms 'more muscular is better'.
Origin
Articulated by evolutionary psychologist Macken Murphy on Modern Wisdom with Chris Williamson, as the predictive lens he applies to women's bodily mate preferences across his research and viral social-media analyses.
Core principles
- 01Women's evolved bodily preferences track cues to a mate's fighting ability, not gym aesthetics
- 02Formidability signalled protection of a partner and offspring in ancestral environments
- 03The optimum is 'could win a fight', which sits below peak leanness or peak muscularity
- 04Personality inferences ride on physique cues, so 'too optimized' can read as mating-effort not paternal-investment
How to run it
- 1
Frame the comparison
Take the two physiques you are comparing and set them side by side rather than judging one in isolation. Preference is relative and revealed by contrast.
Pro tip Use real DXA-verified bodies where possible so you are comparing true body-fat levels, not guesses.
- 2
Ask the fight question
For the two bodies, ask which one looks like it would win in a physical fight. This is the core heuristic that stands in for perceived formidability.
Watch out The winner is rarely the most shredded body; combat-optimised athletes carry more mass and fat than bodybuilders.
- 3
Score the formidability cues
Check the specific signals women report: broad shoulders, big arms, strong veiny hands, height, and enough mass that leanness reads as healthy rather than gaunt.
Pro tip Where mass is carried matters; midsection fat hides abs while leg and glute mass reads as strength.
- 4
Penalise over-optimisation
Discount extreme leanness and dryness. Past the formidability optimum, a physique starts to signal heavy self-beautification, which cues mating-effort over paternal-investment and can become a personality turn-off.
Pro tip Ask whether the look could plausibly be natural; a body that reads as effortless is preferred over one that reads as obsessively maintained.
Watch out Do not confuse men's status-driven approval ('that guy got jacked') with women's attraction; they diverge.
In the wild
William Costello posted before/after photos of a man who cut to roughly 10% body fat. Men strongly preferred the lean 'after'; women strongly preferred the softer 'before'. Applying the fight-winner rule predicts exactly this: the fuller earlier physique reads as more formidable, while the very lean version looks like it lost a famine-fight and signals effortful self-beautification.
→ The heuristic correctly anticipates the sex difference that surprised many male commenters.
Common mistakes
Assuming more muscular always wins
Attractiveness rises with formidability, not with maximal leanness or bodybuilder mass; the optimum sits below what gym culture rewards.
Ignoring the personality inference
A hyper-optimised look cues mating-effort orientation and self-focus, which women read as a worse long-term partner even when the body is objectively impressive.
Is it for you?
Best for
Anyone reasoning about male physical attractiveness, body-composition goals, or evolutionary mate-preference research.
Not ideal for
Judging attractiveness where status, wealth or pre-selection cues dominate over raw physical formidability.
From the transcript
“if you just say like between two guys which of these guys physiques looks like it would win in a fight. Usually the one that…”
“strong veiny hands, big arms, broad shoulders, height, not too lean. All of these things gear towards being formidable.”
From the episode
18 Harsh Realities of Modern Dating - Macken Murphy - #1031
Macken Murphy