In both basic research and applied domains, the prevailing paradigm for assessing social development has shifted from deficit-oriented measures to strength-based assessments or a combination. However, it is not yet clear the extent to which strength-based assessment reflects one end of a single dimension of children’s socio-emotional skills, or a distinctly different dimension from a problem-focused examination. This validation study compares the Social Emotional Assessment Measure (SEAM) with two well-known psychopathological questionnaires (the Caregiver-Teacher Report Form; C-TRF and the Strengths and Difficulties Questionnaire; SDQ-T. We explore the relations between and the variation of the three questionnaires’ scores based on a low-risk sample of 2−5-year-old Danish children (n = 291). The SEAM Empathy Index is directly and positively related to the SDQ-T Prosocial subscale, while the SEAM Self-regulation & Cooperation Index is directly and negatively related to the SDQ-T Conduct problems subscale and the C-TRF Aggressive behaviour and Attention problems subscales. The variation in the SEAM indexes at the floor of the problem-based scales appears to reflect that strength-based assessments measure a distinct aspect of behaviour that is not identical to absence of problem-based behaviour. Thus, positive and negative aspects of socio-emotional skills are not entirely on the same dimension, and strength-based assessment improves the range of information. Abbreviations: Child Behavior Checklist: CBCL; Social Emotional Assessment Measure: SEAM; Strengths and Difficulties Questionnaire: SDQ.