Modern WisdomThe Evolutionary Psychology Of Anxiety & Depression - Ed Hagen
CHAPTERS
- 0:00 – 6:45
Depression as an adaptation: adversity, “psychic pain,” and why it’s so common
Ed Hagen frames depression as an evolved response to adversity—circumstances that historically threatened survival and reproduction. He argues depressive symptoms resemble an amplified version of normal sadness, analogous to physical pain that forces attention onto urgent problems.
- •Depression is widespread compared to rarer disorders like schizophrenia
- •Strong causal link: adversity increases depression risk and vice versa
- •Symptoms are familiar human reactions (sadness, insomnia, appetite change, withdrawal)
- •Evolutionary analogy: depression as “psychic pain” like physical pain
- •Key thinkers referenced: Thornhill, Nesse, Andrews
- 6:45 – 9:22
What counts as “adversity” and why rumination may be functional
They define adversity in evolutionary terms and explore when depression is most likely to activate: when the situation is costly and the solution isn’t obvious. Rumination is presented as a feature—focusing cognition on complex, high-stakes social or resource problems.
- •Evolutionary definition: threats to biological fitness (survival/reproduction)
- •Examples: mate loss, illness/injury, job loss, bereavement, disasters
- •Depression more likely when the solution is unclear and requires sustained thinking
- •Trade-off: shifting cognitive resources away from other tasks
- •Rumination as a core component for many depressed individuals
- 9:22 – 12:34
Personal example: grief, rumination, and downstream protective benefits
Ed recounts his mother’s depression after his father’s death and how her persistent rumination led to increased vigilance about hereditary cancer risks. The story is used to illustrate how depressive cognition might sometimes produce adaptive learning and prevention.
- •Mother ruminates about missed signs of cancer and what could’ve been done differently
- •Rumination may recalibrate attention to future health threats in family members
- •Concrete outcome: Ed gets a colonoscopy; a large polyp is found
- •Illustrates possible long-term benefits despite immediate suffering
- •Reinforces “painful but informative” model of depression
- 12:34 – 14:59
Why depressive symptoms look ‘inactive’: signaling need and recruiting help
Beyond problem-solving, Ed proposes a second function: social signaling. Like crying after injury, depressive behaviors can credibly communicate that something is wrong and that support is needed—especially when individuals can’t solve adversity alone.
- •Pain behaviors can serve as signals of need (tears, crying, facial expressions)
- •Depression may similarly broadcast impaired functioning to social partners
- •Signals can prompt others to infer adversity and offer assistance
- •Fits with the idea that many adversities are socially mediated
- •Depressive withdrawal can be communicative, not just incapacitating
- 14:59 – 18:08
The sex difference in depression: social conflict, anger, and physical formidability
They pivot to the well-known statistic that women report depression about twice as often as men. Ed’s lab emphasizes that depression is often entangled with conflict and anger, and introduces a hypothesis linking depression risk to physical strength rather than sex per se.
- •Women show ~2x higher depression rates; standard explanations remain debated
- •Depression frequently co-occurs with social conflict and anger
- •Conflict resolution across species often involves physical aggression or coercion
- •Upper-body strength strongly predicts success in physical contests
- •Hypothesis: ‘sex difference’ may largely reflect strength differences
- 18:08 – 19:19
Strength vs. depression: handgrip findings and what they imply
Ed describes analyses using a large, nationally representative dataset showing a negative association between upper-body strength (handgrip) and depression. Controlling for strength reduces or eliminates the observed sex difference in depression in some models.
- •Handgrip used as an index of upper-body strength
- •Controlling for strength diminishes/erases sex difference in some analyses
- •Association holds within sexes: weaker men also show higher depression risk
- •Many covariates controlled (SES, age, hormones, health status)
- •Interpretation: strength may reduce depression risk by improving conflict leverage
- 19:19 – 23:11
Can getting stronger reduce depression? Correlation, causation, and why strength (not cardio) matters
Chris presses on causality: is strength protective, or does depression reduce strength? Ed notes exercise helps depression but says the mechanism is uncertain, and argues the relevant pathway is conflict formidability rather than general fitness.
- •Causality question: strength→lower depression vs depression→lower strength vs third variables
- •Exercise has evidence as helpful, but mechanism is unclear in this framework
- •Why strength, not VO2 max or flexibility? Upper-body strength predicts fighting outcomes
- •Model focuses on resolving social conflicts in one’s favor
- •Prediction: high-strength individuals more often prevail, reducing depressive activation
- 23:11 – 25:05
Suicide paradox and sex differences: attempts vs deaths, and method lethality
They address why women attempt suicide more often while men die by suicide more often (common in the U.S.). Ed argues the key phenomenon is attempts, with deaths often an unintended consequence; men’s higher mortality is linked to more lethal methods such as guns.
- •Pattern: higher attempt rates in women; higher completion rates in men (context-dependent)
- •Some populations may differ (Ed mentions China as a possible exception)
- •Attempts-to-deaths ratios: ~10:1 in men vs potentially far higher in young women
- •Core focus: attempts as the behavior to explain evolutionarily
- •Method lethality (e.g., firearms) likely drives much of the male completion gap
- 25:05 – 29:41
Suicide as credible signaling: making need believable under conflict
Ed develops a ‘credible signaling’ model: when there’s conflict, others may doubt claims of suffering or abuse. Suicidal behavior can function as a costly signal that convinces skeptical audiences, because the risk is too high for those not truly in need.
- •Conflict can make others skeptical of one’s claims (e.g., harassment/abuse scenarios)
- •Credible signaling theory: honest signals often require real costs/risks
- •Suicidality framed as a high-stakes signal of genuine need
- •Benefits (help, protection, resources) can outweigh small but real risk of death
- •Explains why attempts vastly outnumber deaths while still producing fatalities
- 29:41 – 35:13
Why natural selection hasn’t eliminated suicide: trade-offs, constraints, and ethnographic patterns
Chris asks why suicide wasn’t selected out. Ed argues the signaling benefits in extreme adversity can maintain the underlying psychology despite lethal edge cases, and he summarizes ethnographic work showing suicide attempts often occur amid conflict and can yield social intervention if survived.
- •Selection can favor mechanisms with benefits despite rare catastrophic outcomes
- •Example: abuse where victim lacks power and needs third-party intervention
- •Ethnographic review: cases vary by sex across societies; data are unsystematic
- •Predicted correlates appear: adversity, conflict, and post-attempt social responses
- •Research is hard due to stigma and community resistance to discussing suicide
- 35:13 – 41:06
Age patterns in depression and suicidality: adolescence, competition, and rising completion risk
They explore why suicidal behaviors spike in adolescence/early adulthood while suicide deaths increase with age. Ed links onset to the transition into mating and resource competition, and notes older bodies may be more vulnerable or may require costlier signals.
- •Depression/suicidality onset: mid-adolescence into early adulthood
- •Peak in behaviors during early adulthood; decline across later life
- •Completions increase with age even as attempts decrease
- •Hypothesis: entry into mating/resource competition triggers more conflict and adversity
- •Possible reasons for older-age completion risk: vulnerability + potentially costlier signaling
- 41:06 – 47:15
Postpartum depression: social support deficits, cooperative breeding, and ‘investment’ signals
Ed explains postpartum depression through a mismatch between the demands of childrearing and available support. He argues postpartum depression often tracks lack of support or infant/maternal health problems, functioning as psychic pain and a signal to kin and partners to increase investment.
- •Postpartum depression appears paradoxical after reproductive ‘success’
- •Strong correlate: lack of support from partner/family; humans are cooperative breeders
- •Cues: low support, unhealthy infant, pregnancy complications, maternal health issues
- •Depression as signal: ‘I can’t do this without more help; conditions must change’
- •Kin and partners have fitness incentives to respond because the child is shared genetic interest
- 47:15 – 53:38
Is evolutionary psychology racist? Human unity, recent population differences, and bad data risks
They turn to controversy: claims that evolutionary psychology embeds race science. Ed argues evo psych emphasizes a shared African origin and minimal time for complex psychological divergence, while acknowledging some journals have published questionable work relying on weak national IQ datasets.
- •Core evo psych view: shared ancestry; cognitive adaptations largely universal
- •‘Races’ framed as recent, mostly superficial adaptations (e.g., skin color, altitude, pathogens)
- •Argument: too little time for large complex psychological differences to evolve
- •Acknowledges problematic papers and misuse of national IQ databases
- •Calls for better research standards and peer review to counter suspect narratives
- 53:38 – 56:34
‘Just-so stories’ critique: hypothesis generation vs empirical testing (and a failed example)
Ed responds that all sciences begin with explanatory stories, but progress depends on testability and rigorous methods. He gives the ovulatory shift hypothesis as an example of an appealing evolutionary idea that larger, better-controlled studies have not supported (so far).
- •‘Just-so stories’ are starting points; the requirement is to test them
- •Evolutionary psychology uses experiments and empirical programs like other sciences
- •Some hypotheses succeed; others fail—this is normal scientific progress
- •Example: menstrual-cycle shifts in women’s mating preferences largely not supported in larger studies
- •Leaves room for future refinements but notes current evidence is unfavorable
- 56:34 – 1:01:30
Music and evolution: synchronized performance as a coalition-quality signal
In the final substantive topic, Ed proposes an evolutionary function for music focused on precise synchrony and shared musical memory. Group musical performance may serve as a hard-to-fake signal of coalition strength and coordination to potential allies or rivals.
- •Music is a long-standing evolutionary mystery (noted since Darwin)
- •Distinctive feature: precise synchronization in joint performance
- •Musical memory appears specialized compared to ordinary verbal memory
- •Costly practice makes synchrony a credible signal of coordination and cooperation
- •Ethnographic support: groups rehearse for weeks/months for short performances at feasts
- 1:01:30 – 1:03:27
Why music feels good, plus where to find Ed Hagen
They briefly discuss why music is rewarding, tying pleasure to behaviors that historically increased fitness via alliance and coalition signaling. The episode closes with Ed sharing where to follow his work and Chris’s sign-off.
- •Pleasure as reinforcement for fitness-enhancing behaviors
- •Performing music can deliver strong positive affect (practice and performance payoff)
- •Coalition signaling framing connects function to felt reward
- •Ed’s online presence: Google/faculty page and @EdHagan on Twitter
- •Closing thanks and outro from Chris
