scripod.com
#1041 - Dr Debra Lieberman - Why Don’t You Have Sex With Your Sister?

Overview

Shownote

Highlights

Transcript

Chapters

Pins

#1041 - Dr Debra Lieberman - Why Don’t You Have Sex With Your Sister?

Modern Wisdom

Jan 03
Modern Wisdom

Modern Wisdom

Jan 03
OverviewShownoteHighlightsTranscriptChaptersPins

Shownote

Dr. Debra Lieberman is an evolutionary psychologist, professor, and researcher. Why don’t we feel sexual attraction toward our siblings or close family? Evolution seems to have hard-wired the brain to prevent inbreeding, a pattern shared with many other a...

Highlights

In this thought-provoking discussion, evolutionary psychologist Dr. Debra Lieberman unpacks the deep-rooted mechanisms that shape human behavior around kinship, attraction, and morality. The conversation dives into the biological and psychological systems that naturally steer us away from inbreeding, while also questioning whether our moral instincts always align with rational reasoning.
00:00
Humans use natural systems to detect close genetic relatives and develop sexual aversion to avoid genetic problems in offspring.
06:28
Breastfeeding by an adoptive mother reduces the likelihood of marriage in 'minor marriage' arrangements due to triggered incest avoidance
13:06
Co-residence from birth reduces uncertainty about genetic relatedness.
15:49
Sharing genes may lead to similar preferences, making relatives seem like one's 'perfect mate'.
24:01
Women show less variation in disgust due to higher reproductive costs.
32:47
Incest porn may appeal due to the fantasy of breaking social norms rather than actual familial desire.
35:27
Cousin aversion could potentially be tuned like sibling aversion due to genetic and social factors.
41:19
Tears can communicate both distress and positive social value, serving as tools for connection or manipulation.
1:03:22
Crying after a breakup might be a neurochemical 'data dump' to reset social attachment.
1:06:28
MediaByte aims to help people access paywalled articles with a late 2026 launch.

Chapters

How do we instinctively avoid falling for family?
00:00
What early life clues help us recognize kin?
06:28
Why being raised together kills attraction
09:59
When biology brings relatives together—emotionally and dangerously
15:49
Why do we feel disgust at incest—even when no harm is done?
21:06
Why is incest a fantasy in porn but taboo in real life?
29:52
Are we too hard on cousin relationships?
35:27
What are tears really saying in social interactions?
38:24
Can crying be both real and manipulative at once?
44:27
What’s next in understanding the mind’s hidden rules?
1:06:28

Transcript

Speaker 2: Why don't people want to have sex with their sister? Speaker 1: Or their brother or other family members? It ends up that humans have a natural inbreeding avoidance system that develops pretty reliably in most folks exposed to the cues, which I...