### Abstract

- Top of page
- Abstract
- A better alternative to using
*α*= 0.05 for null hypothesis significance tests in biological research - The pace-of-life syndrome hypothesis: Live fast, die young?
- Application of the optimal
*α*approach to re-analyze tests of the pace-of-life syndrome hypothesis - Conclusions from pace-of-life syndrome tests sometimes differ between
*α*= 0.05 and optimal*α* - The optimal
*α*approach improves inferences in tests of the pace-of-life syndrome hypothesis - A call for study-specific consideration of significance levels for null hypothesis tests in biology
- References

Setting optimal significance levels that minimize Type I and Type II errors allows for more transparent and well-considered statistical decision making compared to the traditional *α* = 0.05 significance level. We use the optimal *α* approach to re-assess conclusions reached by three recently published tests of the pace-of-life syndrome hypothesis, which attempts to unify occurrences of different physiological, behavioral, and life history characteristics under one theory, over different scales of biological organization. While some of the conclusions reached using optimal *α* were consistent to those previously reported using the traditional *α* = 0.05 threshold, opposing conclusions were also frequently reached. The optimal *α* approach reduced probabilities of Type I and Type II errors, and ensured statistical significance was associated with biological relevance. Biologists should seriously consider their choice of *α* when conducting null hypothesis significance tests, as there are serious disadvantages with consistent reliance on the traditional but arbitrary *α* = 0.05 significance level.