The Twins Data Here is a data set with educational test scores and physical measurements for a sample of high school age identical and fraternal twin pairs. Members of each twin pair were of the same sex. Except for a few cases where the parents were not sure, Twin One was born first and Twin Two was born second. The variables are: ID: Number 1-74 SEX: 0=Male, 1=Female IDENT: 0=Fraternal 1=Identical PROGMAT1: Progressive matrices (puzzle) score for twin 1 REASON1: Reasoning score for twin 1 VERBAL1: Verbal (reading and vocabulary) score for twin 1 PROGMAT2: Progressive matrices (puzzle) score for twin 2 REASON2: Reasoning score for twin 2 VERBAL2: Verbal (reading and vocabulary) score for twin 2 HEADLNG1: Head Length of Twin 1 HEADBRD1: Head Breadth of Twin 1 HEADCIR1: Head Circumference of Twin 1 HEADLNG2: Head Length of Twin 2 HEADBRD2: Head Breadth of Twin 2 HEADCIR2: Head Circumference of Twin 2 The reference is Clark, P. J., Vandenberg, S. G., and Proctor, C. H. (1961), "On the relationship of scores on certain psychological tests with anumber of anthropometric characters and birth order in twins,"Human Biology, 33, 163-180. Here are the data 1 1 1 48 53 66 35 42 61 183 140 522 188 138 535 2 1 1 47 69 88 53 74 84 189 137 542 186 140 543 3 1 1 35 68 92 42 61 86 185 145 549 186 140 550 4 1 1 34 42 73 26 38 68 183 151 544 185 147 545 5 1 1 49 71 95 38 72 97 174 145 534 186 143 543 6 1 1 50 90 122 46 82 101 191 143 551 191 141 552 7 1 1 25 30 42 28 37 43 184 143 511 186 143 535 8 1 1 25 74 64 41 78 65 180 146 532 179 144 527 9 1 1 23 19 52 23 36 59 193 146 560 191 145 551 10 1 1 26 40 61 16 37 50 174 139 505 174 138 500 11 1 1 40 63 88 40 54 90 183 150 544 192 147 556 12 1 1 43 53 58 48 60 85 178 147 531 177 150 534 13 1 1 44 69 95 34 86 106 186 137 532 185 140 536 14 1 1 29 50 84 43 69 96 183 148 538 186 146 541 15 1 1 21 64 72 33 59 63 191 155 570 183 158 565 16 1 1 30 56 65 26 51 75 178 151 533 176 154 540 17 1 1 38 64 102 31 48 95 169 142 511 174 145 523 18 1 1 31 44 65 33 31 60 176 140 512 177 138 508 19 1 1 41 88 129 52 85 130 198 147 563 194 147 560 20 1 1 27 34 48 38 55 40 188 141 542 189 138 537 21 0 1 45 47 56 37 40 55 175 159 534 177 150 531 22 0 1 40 30 48 41 25 59 177 145 531 181 144 520 23 0 1 48 55 80 50 58 60 195 148 551 196 147 552 24 0 1 42 51 72 46 55 57 190 150 555 191 148 557 25 0 1 45 51 83 31 57 101 187 135 516 181 137 518 26 0 1 44 60 83 39 40 60 195 152 562 197 148 555 27 0 1 40 43 46 37 51 56 186 156 560 174 159 546 28 0 1 37 37 46 42 20 40 180 148 530 182 145 529 29 0 1 27 36 37 27 29 22 185 148 536 184 148 536 30 0 1 45 72 98 48 82 114 186 160 547 181 161 552 31 0 1 51 46 128 49 62 124 193 157 566 192 155 551 32 0 1 44 47 92 52 45 94 192 140 542 195 141 545 33 0 1 44 64 64 27 46 60 186 149 542 187 146 544 34 0 1 29 49 38 36 33 37 193 150 556 190 154 558 35 0 1 27 20 39 29 18 25 192 147 549 195 144 552 36 0 1 48 62 71 44 53 88 199 153 573 198 149 571 37 0 1 33 30 86 44 46 93 199 145 555 191 147 550 38 0 1 39 54 51 43 41 59 190 156 554 193 153 558 39 0 1 47 73 86 34 70 78 191 151 560 194 149 555 40 0 1 54 63 92 48 62 101 208 154 586 205 153 583 41 0 1 32 39 93 33 35 87 191 148 554 185 148 546 42 1 0 48 85 73 40 82 65 185 146 543 188 146 557 43 1 0 39 69 119 48 76 126 197 147 560 190 142 542 44 1 0 50 75 115 53 57 99 179 151 541 185 155 565 45 1 0 44 62 59 44 46 43 183 141 532 176 136 514 46 1 0 36 31 65 35 36 45 169 135 491 180 140 521 47 1 0 35 68 87 20 67 82 190 145 547 182 142 528 48 1 0 50 88 110 52 82 100 185 144 548 178 141 525 49 1 0 37 47 69 33 37 46 172 145 525 175 146 525 50 1 0 32 65 93 42 67 71 180 145 529 173 145 524 51 1 0 29 61 85 37 61 85 179 142 529 181 143 534 52 1 0 21 32 60 17 30 32 179 140 514 181 134 523 53 1 0 17 72 90 32 60 80 183 141 532 191 146 543 54 1 0 26 25 55 22 41 41 192 144 555 174 141 524 55 1 0 28 31 26 11 34 24 193 145 562 191 140 552 56 1 0 47 47 67 40 53 63 183 151 548 184 145 545 57 1 0 46 68 96 43 58 82 187 142 536 177 137 512 58 1 0 30 51 49 27 52 49 183 143 536 179 140 522 59 1 0 34 58 65 47 52 78 177 146 518 182 140 528 60 1 0 11 41 61 36 41 63 190 153 550 182 139 530 61 1 0 42 77 68 44 56 67 186 147 553 187 147 547 62 0 0 58 91 128 54 73 129 192 146 561 195 144 561 63 0 0 44 46 79 42 34 42 184 136 521 189 136 534 64 0 0 44 43 70 43 36 58 187 150 540 187 151 541 65 0 0 36 40 63 42 39 63 196 153 568 186 159 553 66 0 0 34 21 53 45 31 70 186 150 549 194 147 559 67 0 0 50 70 93 45 67 109 200 158 581 198 156 575 68 0 0 50 81 101 41 47 96 198 150 557 195 144 555 69 0 0 31 76 122 43 70 75 195 158 569 199 148 564 70 0 0 23 29 62 26 29 42 181 159 548 190 152 556 71 0 0 52 66 114 42 69 120 190 155 558 182 159 554 72 0 0 48 51 62 30 35 49 187 147 542 186 154 550 73 0 0 23 48 78 38 62 87 179 162 548 187 165 563 74 0 0 28 38 62 55 70 105 199 155 564 204 154 580