Temperament influences maternal behavior and lamb survival in Merino sheep selected for calm or nervous temperament. The impact of this selection oil mother-young recognition and early expression of temperament ill lambs is unknown. We tested the ability of multiparous elves selected for calm (n = 16) or nervous (n = 18) temperament to recognize their own lambs 6 hr after parturition, the ability of the lambs to display a preference for their own mother at 18 hr; and the temperament of the lambs at 1 and 16 weeks of age. Elves and lambs from both genotypes showed a similar preference for their familiar kin. In contrast, differences lit temperament were detectable at l and 16 weeks of age. Nervous lambs showed higher vocal and locomotor activity than calm lambs. Thus, temperament did not affect the early process of ewe-lamb bonding but might affect the quality of the mother-young relationship under more challenging situations. (C) 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 429-438, 2009.