Many statements of bias evidence open hostility toward the protected class, and are thus readily recognizable as direct evidence of discriminatory animus. However, certain statements that are not openly hostile are less readily recognizable as discriminatory. However, subtle generalizations about target groups can be used as powerful evidence that the group status of a plaintiff-employee was considered when an employer has taken adverse action against the employee. The Supreme Court had long recognized that unlawful discrimination can stem from stereotypes and other cognitive biases, as well as conscious animus, the First Circuit has reiterated that "the disparate treatment doctrine focuses on causality rather than conscious motivations, since 'unwitting or ingrained bias is no less injurious or worthy of eradication than blatant or calculated discrimination.' " Thomas, supra, at 60 (citing Hopkins v. Price Waterhouse, 825 F.2d 458, 469 (D.C. Cir. 1987), aff'd, Price Waterhouse v. Hopkins, 490 U.S. 228, 109 S.Ct. 1775 (1989)). The First Circuit further stated:
The concept of "stereotyping" includes not only simple beliefs such as 'women are not aggressive' but also a host of more subtle cognitive phenomena which can skew perceptions and judgments. Price Waterhouse highlighted one such phenomenon: the tendency of "unique" employees (that is, single employees belonging to a protected class, such as a single female or a single minority in the pool of employees) to be evaluated more harshly in a subjective evaluation process.... Other types of biased thinking are also widely recognized.
Thomas, supra, at 61 (citations omitted). See also Eldred v. Consoldiated Freightways Corp. of Del., 898 F.Supp 928, 934 (D. Mass. 1995) (employer's assertions that plaintiff lacked "aggressiveness" and was too "soft" supported "unavoidable conclusion" that plaintiff was passed over for promotion because of her gender).