The purpose of this communication is to challenge the "evidence" for higher olefin incorporation into the Fischer-Tropsch (FT) products in secondary reactions and dispute the claims that these postulated reactions are responsible for the "positive deviations" from the Anderson-Schulz-Flory (ASF) distributions. Furthermore, arguments and information are presented to show that multiplicity of the chain growth probability is the only reasonable cause of the reported "positive deviations" in the C6+ product range. (C) 2003 Elsevier B.V. All rights reserved.