Maurycy Gottlieb Gottlieb settled in Kraków and began working on his new major project. He died in the same year from health complications. Matejko attended his funeral and promised his father to look after his younger brother Marcin. Gottlieb won a gold medal at the Munich art competition for his painting, "Shylock and Jessica" (1876), portraying a scene from Shakespeare's "The Merchant of Venice". The painting was exhibited in Lviv in 1877, and in 1878 at "Zachęta" in Warsaw and widely acclaimed. Gottlieb based Jessica's face on that of Laura Rosenfeld, to whom he had proposed marriage. However, Laura rejected his proposal
Gilbert Gottlieb measured characterized this "critical period" with an "appropriate" independent variable. Gottlieb suggests that imprinting may be the result of a series of complex and subtle feedback processes. Gottlieb continued his research involving birds by depriving mallard ducks of auditory sensory stimulation experienced in normal development. He then exposed them to both chicken and mallard calls. He found that instincts do not solely depend on experience, but influential social situations. Gottlieb's major contribution to psychology was his theory of probabilistic epigenesis, which states that behavioral development does not have a predetermined course. He described "experiential effects as facilitating, inducing, and maintaining