turns out they are. new research suggest a big chunk of our confidence, some say up to 50%, comes straight from our dna. i was busy researching the origins of confidence and i set out to learn my genetic blueprint. one saliva test and the help of a doctor, i learned in terms of the key genes which contribute to confidence, i come up short. i'm more prone to anxiety than resilience and more of a worrier than a warrior. that's one part after larger confidence equation. hormones like testosterone give men a boost. and the parts of our brain matter. women rely more heavy on a section called worry wart, for example, but even if you are a worrier like i am, you can overcome the cards you were dealt at birth. >> we have potential to rewire our brains. in the brain, practice doesn't make perfect. practice makes permanence. >> reporter: it's what scientists brain plasticity. we can create more confident pathways in our brain with better habits. some of the best, especially for women, embrace failure.