FIGURE 22.1 Other animals also display face smarts After repeatedly experiencing food rewards associated with some sheep faces, but not with others, sheep remember those faces for two years (Kendrick & Feng, 2011).
Reprinted by permission by Macmillan Publishers Ltd: Nature, “Sheep Don’t Forget a Face,” Keith M. Kendrick, Ana P. da Costa, Andrea E. Leigh, Michael R. Hinton & Jon W. Pierce Vol. 414, November, 2001, p. 165.