Studies

• Method: Lorenz dived goose eggs into two groups 

  • one with natural mother
  • Other group placed in incubator, Lorenz made sure that he was the first moving object goslings saw

  After eggs hatched and had seen mother or Lorenz he marked the two groups and returned them to their natural mother 
• Results: geese that hatched in the incubator continued to follow Lorenz while those that hatched naturally continued to follow their natural mother 

  • chicks who saw Lorenz before anything else followed him as if he was the mother, when they were adult they performed mating displays to him, ignored other geese
• • Lorenz also found that goose chicks seemed to have a critical period of 4-25 hours after hatching in which to imprint 
  • If they didn’t imprint within this time they never would 
• Kaluchova 1976, 1991

  • Czech twin boys discovered to have spent years of their lives locked up by stepmother as their own mother died when they were babies
  • Stepmother was cruel beating both children
• Kaluchova 1976, 1991

  After being fostered by two loving sisters and accessing learning supportive school, Both twins recovered well having excellent relationships with foster family and own children later in life
• Kaluchova 1976, 1991 supports bowbly study :

  Monotropic- undersized, language and social difficulty’s 
• Kaluchova 1976, 1991 Refutes study:

  Critical period - 2 1/2 years, still recovered and were able to develop healthy relationships later in life