Ask most people what separates someone who commits a crime from everyone else and the instinctive answer runs along the lines of worse, harder, colder. After three interview episodes with Professor Dai Shen-feng on the Bo-Yin podcast, I came out with something different: the most unsettling thing about crime is how close its psychology sits to ordinary psychology. The difference is that certain people crossed a line at a certain point. This entry rebuilds the three episodes (crime genes, drugs, sexual offences) into a single causal chain. The section on sexual offences covers cases and the cognitive distortions of offenders, so go in knowing that.
# One. Disposition: Genes Hand Over a Weak Point, Environment Decides Where It Goes
Criminology started hunting for crime genes in the 1980s and did find several.
The warrior gene makes people driven, willing to fight, carrying a streak of the wolf about them, and the people who carry it also succeed conspicuously. Men with an XYY chromosome may have somewhat weaker self-control, and their proportion runs slightly higher among serial sexual offenders.
Professor Dai added a line immediately: all that can be said is that more of them got caught. The idea that carrying the gene produces crime has nothing behind it.
Nature hands over a weak point at most. Crime surfaces when that weak point happens to get stepped on by a sore spot in society.
"You carry certain weak points, society happens to step on a sore spot, and the crime simply surfaces."
EP182 · 23:57
Which weak points get stepped on most easily? Professor Dai named three.
Neurotic people act on impulse and inflate situations. Hostile people read neutral situations as aimed at them — a friend late because of traffic becomes you are deliberately holding me up; a priority-seat confrontation on the metro becomes you are sitting there to refuse me on purpose. People with antisocial leanings want to test the rules, and running an amber light feels like a win.
All three traits still sit some distance from crime. Among people carrying the same impulsive trait, some became founders, some became athletes, and some went towards crime. Innate conditions amount to a disposition. What they actually do is make the next step easier to reach.
# Two. Formation: The Most Important Fuel for Crime Is Success
The common assumption is that the heart goes bad first and crime follows.
What Professor Dai mostly sees runs in the other order: it starts with one small test.
A little alcohol on the road and nothing happens, so next time one more glass feels safe. Scam money mules collect far more often than they get caught, with hundreds of successful runs behind the one arrest. Every time nobody catches them, the message lands: this is easy to do.
"The occurrence of crime is itself an important tool for suppressing crime."
EP182 · 37:45
Do it and the odds of being investigated, imprisoned and sentenced are high, and the next opportunity gets taken away. Most people's self-control mechanism holds up on exactly that. The real trouble sits with the people who got away with it again and again and grew on it.
Drugs run the same road. The first pill delivers a high several times beyond anything imagined, and the brain files it. Afterwards no amount of chasing gets back to that height, and tolerance makes each round weaker than the last. Professor Dai borrowed an old line: once you have seen the ocean, no water impresses you again.
The following section covers sexual offence cases and the cognitive distortions of offenders. The content may be distressing, so read at your own discretion.
Sexual offences push this mechanism to its furthest point.
The source of the high reaches well past sex itself: pressing the shutter brings pleasure, so does a flick of the eyes. What it connects to is control — the sense of superiority produced by the information gap of "I know something you do not." Sex is merely the object that this pleasure attaches to.
That is also why Professor Dai holds reservations about chemical castration: hormone treatment addresses libido, and the core sense of control stays untouched.
Drunk driving, fraud, drugs, sexual offences — four separate things on the surface, one circuit running underneath:
# Three. Entrenchment: Why It Does Not Come Off
Once the circuit is built, two forces lock it in place.
The first is cognitive rationalisation.
Professor Dai interviewed a man who killed his own sibling to claim insurance money and drew a life sentence. Twenty years on, elderly and blind, the man sat down and immediately protested his innocence: I never fired the gun, I never got the money. His own close relative gone, twenty years served, and that account still holds together intact.
Another money mule case carries the same thing. A man in his early twenties took NT$300,000 from an elderly woman and got caught on the third attempt. Professor Dai asked him: what if it were your own grandmother losing NT$300,000 one day? The man jumped up on the spot and said he would kill whoever did it. Capable of it against someone else's grandmother, unable to tolerate an inch of it against his own.
Professor Dai says most of these people are deeply unused to expressing emotion, and unused to other people having emotions. What they genuinely lack is one relationship capable of pulling them back into ordinary life.
The second is cue retrieval.
Craving gets hooked out by cues — a particular person, a particular scene, a particular emotion, and the addiction gets drawn out. It works the same way as not wanting coffee in the middle of the night until the smell of it arrives.
Professor Dai described a case from the Taichung women's prison.
A mother was pulled in by her husband through using together. He was arrested soon after, she found she was pregnant, and she carried her daughter to term and raised her while using in small amounts. On the day her daughter started primary school, she looked at the other parents, polished and presentable, and at her own arms covered in needle marks that only long sleeves could hide, and decided then to quit. She ran a noodle stall and put her daughter through university.
Sixteen years clean, and eventually she stopped counting the days at all.
Then it came apart at her daughter's graduation. Her daughter had passed the civil service exam, arrived with a steady partner, and told her: these years have been hard on you, Mum, you can relax a little. Relax a little was precisely what that first needle had felt like. The cue reconnected in an instant. She went looking for the old contacts, and there was no coming back.
"Her 'relax a little' back then came from that needle; those four words pulled the whole association straight back out."
EP203 · 34:04
The kind of quitting held up by willpower is what Professor Dai calls grit-based abstinence. Still counting the days means the person is still tied to it — like someone counting the days since a breakup, where the ones who have genuinely moved on stop counting.
So his position is to replace quitting drugs with leaving drugs: leave the cues, leave the environment, grow new connections inside the brain's reward circuit, and fill the gap with rewards that are smaller, faster and legal.
It holds for drugs, for crime, and for sexual offences. The same thing is stuck in place: the brain already knows this works. The circuit is built, and willpower cannot dismantle it.
# Four. Intervention: Where to Start
Start with the data.
On Taiwan's figures, roughly 80% of sexual assaults are committed by someone known to the victim. Close to half of those involve family or relatives. Among victims under eighteen, roughly 90% of offenders are people the child knows. Genuine random attacks by strangers sit below 10%.
"Most sexual assault, on Taiwan's data, is around 80% acquaintance assault; and within acquaintance assault, close to half is by family or relatives."
EP229 · 07:27
What genuinely warrants vigilance is usually a situation that cannot be walked away from.
Professor Dai used a street-lamp analogy. Given an alley in total darkness and an alley with a single street lamp, most people take the lit one. The problem is that the light frames your vision, and the dark beyond the lamp becomes harder to read; the person intending harm is standing right beside the lamp, seeing you approach in full detail. Offenders prefer locations with open sight lines and easy exits. Shopping-centre toilets make this obvious: the layout with men's and women's rooms at opposite ends is considerably safer than one with an accessible family room in the middle that anyone can walk into.
Holding on to this way of reading dangerous environments is more useful than holding on to the face of a bad person.
On drug policy, Professor Dai lays the spectrum out: from decriminalisation and depenalisation, to treating it as illness, through to Taiwan's current position of criminalisation with penalties. Over these years the consensus has been shifting one notch at a time towards the treatment end. What has genuinely produced results in Taiwan is methadone substitution and harm reduction.
For sexual offences he offered three directions. Draw the red line clearly and attach penalties, so that the 90%-plus who have entertained the thought stop once they know where the line sits. Wait for psychiatry to find the pathological basis, so medicine can intervene in the genuinely abnormal fraction. Gender-balance education — he chose the word balance, because men and women still occupy different positions in the social structure.
Reoffending is the hardest piece. One offender surnamed Lin served seven years and, on release, told prison staff not to let him out. Within two weeks he committed the rape and murder of a young girl. That case produced post-sentence compulsory treatment.
The controversy sits here: the sentence is complete, and the person stays confined on a judgement that they will reoffend. Criminal law currently holds three options in hand — confinement, penalty, taking life — and medicine cannot get in.
He also noted that nearly every one of these institutional advances in Taiwan was built on tragedy. Behind the Domestic Violence Prevention Act stands Deng Ru-wen. Behind gender equity education stands Yeh Yung-chih.
The three episodes each cover a different subject. Rebuilt into one chain, the thread becomes clear:
Every link in it is a point where intervention can land. Move the lens off the person and onto the situation that came before the person, and the things worth doing surface.
Note
This entry is assembled from three Bo-Yin podcast conversations with Professor Dai Shen-feng: crime genes, drugs, sexual offences. The figures and cases are all as stated by Professor Dai in the programme. Quoted lines carry the sense of what was said with a jump-to timestamp on the original video attached. Details involving victims have been blurred. The article is reorganised along causal logic, and the playback order follows the three original videos.