twins                  package:alr3                  R Documentation

_B_u_r_t'_s _t_w_i_n _d_a_t_a

_D_e_s_c_r_i_p_t_i_o_n:

     The given data are IQ scores from identical twins; one raised in a
     foster home, and the other raised by birth parents.

_F_o_r_m_a_t:

     This data frame contains the following columns:

     _C Social class, 1=high, 2=medium, 3=low

     _I_Q_b biological

     _I_Q_f foster

_S_o_u_r_c_e:

     Burt, C. (1966). The genetic estimation of differences in
     intelligence: A study of monozygotic twins reared together and
     apart. _Br. J. Psych._, 57, 147-153.

_R_e_f_e_r_e_n_c_e_s:

     Weisberg, S. (2005). _Applied Linear Regression_, 3rd edition. New
     York: Wiley, Problem 6.16.

_E_x_a_m_p_l_e_s:

     data(twins)

