Assumptions of strong, causal relations between cognition, language, and affection are often made in general and in bilingualism in particular. This paper presents first a set of hypotheses concerning the relation between affection and language in bilingualism. One subset is concerned with language learning, language maintenance, and mental health in migrant children, another with the critical period theory for language learning. A second set of assumptions is concerned with the relation between affection and cognition in general. A third set of hypotheses considers the relationship between language and cognition. Research and statements regarding the three sets are reviewed. The actual relationships are studied by means of canonical correlations, and compared with averaged simple correlations. No systematic correlations between language and emotion, and cognition and emotion could be found. However, the associations between language and non-verbal intelligence, reading and intelligence, and language and reading were found to be substantial. The results agreed with recent neuropsychological, endocrinologic, and perceptual research. Contains 88 references. (Author/LB)