Are bigger flakes always better? An experimental assessment of flake size variation on cutting efficiency and loading

Previous studies have indicated that the cutting efficiency of flake tools increases with increased tool size. Here, we undertook to examine the relationship between flake size and efficiency parameters using a larger and more variable flake dataset than used in previous analyses. Our analyses were specifically designed to assess whether there is an absolute relationship between ever-increasing flake size and increased efficiency and/or loading potential. An alternative hypothesis is merely that only the smallest flakes are inefficient, and it is this factor which has been driving previous statements linking increasing flake size with increased efficiency. Our first set of analyses, using all experimental flakes, determined that a statistically significant relationship existed between increased flake sizes and increased cutting efficiency, as measured by two different efficiency measures ('Time taken' and 'Number of cutting strokes required'). This analysis also demonstrated a statistically significant positive relationship between flake size and loading forces. However, our second analysis, which excluded the smallest flakes in our sample, revealed a different pattern. In this second set of analyses, increasing flake size did not indicate a statistically significant relationship with our two measures of cutting efficiency. A statistically significant relationship between increased flake size and increased loading was, however, still evinced. In sum, these results suggest that there is not an unconditional or absolute relationship between increased flake size and increased cutting efficiency in all circumstances. Rather, there is a threshold below which flakes of a certain size will become markedly inefficient. Our results have particular implications relating to flake utility, optimality, and factors potentially influencing flake selection by hominins.