Three studies showed that the group of observers accurately recognized biases in other people's behaviors while the group of actors was unable to detect the same biases in their own behaviors. The logic and inevitability of biases influenced the estimations of the former. Biases which were positive, beneficial, logical and non-threatening for the self but at the same time uncontrollable were perceived as more accurate by the group of actors. The correlations among the characteristics of biases themselves and between characteristic of biases and the accuracy are suggested as possible explanations. The theoretical background of the studies is embodied as well in tendency-oriented theories (Kahneman & Tversky, 1973; Fiske & Taylor, 1984; Kruglansky, 1989) as in new stream of accuracy theories (Haselton & Buss, 2000; Funder, 1995; Levesque, 1997; Simson, Ickes, & Grich, 1999). (Contains 2 tables and 4 figures.)