- Rule of thumb suggests longer digits mean bigger brains The Times
- Human dexterity and brains evolved hand in hand – Communications Biology Nature
- Primates with longer thumbs tend to have bigger brains, research finds The Guardian
- Long Thumbs and Large Brains Co-Evolved in Primates, Giving Humans Our Most Unique Traits Discover Magazine
- Study Links Thumb Length to Brain Size and Cognition Neuroscience News
Rule of thumb suggests longer digits mean bigger brains – The Times
