This study is concerned with preservice primary school teachers (N=100), a group of tertiary students who traditionally come from the secondary school stream. These students have, on the whole, avoided subjects like physics, chemistry, and mathematics that demand a high level of cognitive development for understanding/assimilation of abstract concepts. The study focuses on the cognitive developmental levels of these individuals on leaving the training institution and considers implications for elementary science by sampling science teaching styles. Results indicate that final year students in the transitional stages of cognitive development exhibit teaching behaviors in elementary science lessons of a higher quality than those who are in concrete or formal operational stages. This suggests that concrete operational students entering teacher preparation programs must be identified and given opportunities to develop to higher cognitive levels. Formal operational students constitute a different problem. These students are undoubtedly capable of conducting lessons of a high cognitive level but appear to lack understanding of the intellectual problems facing children, probably because they cannot relate to problems of abstract reasoning not encountered by themselves. Since both concrete and formal students tend to conduct less practical, "hands-on" science lessons than transitional students, strategies fostering such teaching methods need to be considered. (JN)