The paper presents the summary of the special issue of "JMMD" "Ethnolinguistic vitality". The volume shows convincingly that ethnolinguistic vitality perceptions as measured by standard methodology such as the Subjective Ethnolinguistic Vitality Questionnaires (SEVQ) are not reliable indicators of actual vitality. Evidence that ethnolinguistic behaviour is more affected by social structural factors and by members' motivations than by their subjective vitality perceptions is summarised. Based on these findings, it is proposed that ethnolinguistic vitality, i.e. the group's ability to behave as an active collective entity, depends on the emotional attachment of its members to this collective identity. This suggests that when high vitality is achieved by affective involvement, the rational arguments for being aligned to one or the other group measured by SEVQ lose their force. From this it follows that groups have two prototypical modes of operation, "hot" and "cold", or a scale of modes between these extremes; and that ethnolinguistic vitality is achieved at least to some extent by different means in different modes. An overview of factors affecting ethnolinguistic vitality modes is presented.