The present invention relates to a viscosity modifier represented by the following general formula (1), and an emulsion composition or an aqueous paint composition including the viscosity modifier: where: R1 to R4 each represent a linear alkyl group having 1 to 13 carbon atoms; R5 and R6 each represent a group represented by the following formula (2) or (3); m and n each represent a number from 3 to 15; x represents a number from 40 to 800; and y represents a number equal to or more than 1, provided that each of a total number of carbon atoms in R1 and R2 and a total number of carbon atoms in R3 and R4 needs to be from 10 to 14.