Kevin MacDonald, Ph.D.
CSULB, Department of Psychology
Psychology 346IC
BIRTH ORDER
FRANK SULLOWAY'S BORN TO REBEL: BIRTH ORDER, FAMILY DYNAMICS, AND CREATIVE LIVES (NY: PANTHEON, 1996)
1.) INDIVIDUAL DIFFERENCES IN PERSONALITY:
a.) PERSONALITY TRAITS ARE HERITABLE: 50% OF VARIATION IS DUE TO VARIATION IN GENES;
50% OF VARIATION IS DUE TO VARIATION IN ENVIRONMENT;
MUCH OF THE GENETIC VARIATION IS NON-ADDITIVE (i.e., EMERGENIC);
THEREFORE: GENETIC VARIATION DOES NOT MAKE SIBLINGS IN THE SAME FAMILY RESEMBLE EACH OTHER
b.) 50% OF VARIATION IN PERSONALITY TRAITS IS DUE TO VARIATION IN THE ENVIRONMENT;
MOST OF THE ENVIRONMENTAL VARIATION IS UNSHARED;
THEREFORE: ENVIRONMENTAL INFLUENCES ON PERSONALITY TEND TO MAKE CHILDREN IN THE SAME FAMILY DIFFERENT FROM EACH OTHER.
RESULT: FOR GENETIC AND ENVIRONMENTAL REASONS, SIBLINGS DO NOT RESEMBLE EACH OTHER IN PERSONALITY
SULLOWAY: BIRTH ORDER IS MAIN SYSTEMATIC ENVIRONMENTAL REASON WHY SIBLINGS DIFFER FROM EACH OTHER.
SEX IS ALSO IMPORTANT: GIRLS ARE TREATED DIFFERENTLY THAN BOYS
BIRTH ORDER: A PROXY FOR DIFFERENCES IN AGE, SIZE, POWER, AND PRIVILEGE
EACH CHILD ATTEMPTS TO OCCUPY A NICHE WITHIN THE FAMILY;
OLDEST CHILD OCCUPIES THE FIRST AVAILABLE NICHE;
IDENTIFIES WITH PARENTS AND WITH AUTHORITY; TENDS TO REJECT NEW IDEAS;
YOUNGER CHILDREN: BORN TO REBEL; OPEN TO NEW EXPERIENCE AND IDEAS; OFTEN RESENTS TREATMENT BY PARENTS AND OLDER SIBS;
LESS LIKELY TO IDENTIFY WITH PARENTS AND CONSERVATIVE BELIEFS OF FIRSTBORN
EVOLUTIONARY FRAMEWORK
PARENT-OFFSPRING CONFLICT:
INFANTICIDE AND NEGLECT OF LATER BORN:
PARENTS FAVOR OLDER, HEALTHIER CHILDREN IF THEY HAVE TO MAKE A CHOICE;
JAPAN: LATER BORN ARE 'COLD RICE'
MORTALITY OF LATER-BORNS IS HIGHER THAN FOR FIRST- BORNS; THEY HAVE LOWER STATUS;
PRIMOGENITURE
SIBLINGS HAVE CONFLICTS OF INTEREST:
SAND SHARKS: YOUNG EAT EACH PRIOR TO BIRTH OTHER UNTIL ONLY ONE (WELL-FED) SHARK IS LEFT TO BE BORN;
PREDATORY BIRDS (e., g., BOOBIES): LAY ONE EGG MORE THAN PARENTS CAN REAR IN BAD YEAR;
WHEN BODY WEIGHT OF OLDER CHICK IS LESS THAN 80% OF NORMAL, IT KILLS YOUNGER SIBLING;
PARENTS DO NOT INTERVENE AND SOMETIMES PARTICIPATE;
CHILDREN: COMPETE FOR RESOURCES FROM PARENTS AND SIBLINGS
STRATEGIES:
1.) CURRY FAVOR WITH PARENTS; e.g., OBEDIENCE
2.) DOMINANCE BEHAVIOR
3.) RESIST DOMINANCE: REBELLION, APPEASEMENT, etc.
TABLE 4; FIGURE 3.2
PERSONALITY AS ADAPTIVE STRATEGIZING
NICHE DIVERGENCE:
SIBLINGS (LIKE DIFFERENT ANIMAL SPECIES) OCCUPY DIFFERENT NICHES
ENVIRONMENTAL SOURCES OF VARIATION:
1.) PSYCHOLOGICAL EFFECTS OF PARENTAL DISCRIMINATION IN FAVOR OF OLDER CHILDREN:
e.g., DICKENS' Vignette from Sulloway.
2.) SIBLING COMPETITION: SOCIAL COMPARISONS RESULT IN SIBLINGS HAVING DIVERGING INTERESTS;
CONTRAST EFFECTS: THE NADER SIBLINGS
CHILDREN IDENTIFY WITH DIFFERENT PARENTS
DEFENDING A NICHE: (P. 100)
FIRSTBORNS: SOCIALLY DOMINANT AND DEFENSIVE; FIRSTBORNS WERE 3.2 TIMES AS LIKELY TO INITIATE PRIORITY DISPUTES IN SCIENCE
LATERBORNS: MORE ACCOMMODATING AND MAGNANIMOUS
OPENNESS AND DIVERSIFICATION: FIRSTBORNS: NARROW INTERESTS
LATERBORNS: BROAD INTERESTS, 'DIVERGENT THINKING'
OTHER MODERATING VARIABLES:
PARENT-CHILD CONFLICT: CHILD REJECTS AUTHORITY;
MAKES FIRSTBORNS INTO REBELS;
NOT AS MUCH EFFECT ON LATERBORNS;
SHYNESS:
SHY FIRSTBORNS ARE MORE OPEN TO SCIENTIFIC INNOVATION; SHY LATERBORNS LESS LIKELY TO BE RADICALS
EXPLANATION: SHY FIRSTBORNS LESS LIKELY TO BE AGGRESSIVELY CONSERVATIVE;
SHY LATERBORNS LESS LIKELY TO BE AGGRESSIVELY RADICAL
