A necessary (or sine qua non) condition is one without which development would not be forthcoming. Such conditions have been sought in deprivation studies. A sufficient condition is one with which development does occur, and as such has been the concern of enrichment or special experience studies. Necessary and sufficient conditions do not have to be causal in nature; they may be causally connected with what it is they are a condition of, without being the cause of it (e.g., a behavioral or brain state may be a necessary condition for selective attention, but it is not the cause of it). Having read this entry, you may think the distinction between necessary and sufficient. In terms of making decisions, it can be quite complicated process,
See Antecedent-consequent relationships, Causality (in philosophy), Co-factor, Essentialism, Moral development, Radical behaviorism (or environmentalism), Sphericity assumption