TWIL #057 - Identical Twins Separated at Birth Draw Remarkably Similar Pictures
Twins raised in completely different countries, with no contact, independently produce strikingly similar drawings - suggesting that aesthetic preferences have a stronger genetic component than most people expect.
- #psychology
- #science
- #biology
The Minnesota Study of Twins Reared Apart (1979–1999), led by Thomas Bouchard at the University of Minnesota, was one of the most extensive investigations into nature vs nurture ever conducted. Researchers located monozygotic (identical) twin pairs who had been separated in infancy and raised in entirely different families, often in different countries, with no contact between them.
When reunited as adults, the twins were given extensive psychological, medical, and behavioural assessments.
The findings across the board were striking:
- Twins separated at birth showed similar IQ scores - with heritability estimates for intelligence around 70%.
- They had similar personality profiles on standardised measures: extraversion, conscientiousness, neuroticism.
- Many had independently chosen the same hobbies, the same careers, the same car colours, and even the same names for their children and pets.
- Medical histories were surprisingly similar: similar age of onset for illnesses, similar teeth problems, similar weight trajectories.
The drawing studies: Among the assessments given to twins were open-ended creative tasks - including being asked to freely draw. Pairs who had never met produced drawings with similar compositional choices: similar proportions, similar placement of elements, similar levels of detail, similar stylistic quirks (rounded vs angular, sparse vs detailed). This held even for tasks as simple as drawing a mountain or a tree.
This was not universal - environment does shape aesthetic output - but the degree of similarity was statistically far beyond what chance would predict.
What this suggests: Artistic preference and creative style have a meaningful genetic component. The way a person tends to compose space, choose detail, and resolve visual problems appears to be partly heritable - not learned entirely from environment, culture, or instruction.
The limits: Critics of the Minnesota study note methodological limitations: small sample sizes for some trait pairs, potential for confirmation bias in reporting, and the difficulty of ruling out shared prenatal environment. But the broad finding - that genetics explains substantially more of personality and preference than intuition suggests - has been replicated across multiple twin studies.