| Starting intellectual assumptions |
| Negative biology: Health, longevity and happiness are assumed to be a ‘given’, or part of ‘normal species functioning’, for humans. |
| Positive biology: There is diverse variation in the genotypes which influence desired phenotypes, such as health. The evolutionary and life history of different species helps explain this variation and the different biological tradeoffs that determine age of reproduction, body size, senescence, complexity of the brain, etc. |
| What needs to be explained? |
| Negative biology: The proximate causes of disease, frailty and disability. |
| Positive biology: The proximate and ultimate causes of exceptional health, positive emotions and happiness, high cognitive ability, etc. |
| Which kinds of interventions ought to be pursued? |
| Negative biology: Interventions that help prevent, treat and cure specific diseases. |
| Positive biology: Interventions that increase the opportunities for health, happiness and wellbeing. |