$ for i in file[12] ; { print $i ; cat $i }
file1
Adam    1 2 3
Eve     4 5 6
file2
Adam    4 5 6
Eve     7 8 9

$ join -1 1 -2 1 file1 file2
Adam 1 2 3 4 5 6
Eve 4 5 6 7 8 9