add_action( 'show_user_profile', 'my_show_extra_profile_fields' );
add_action( 'edit_user_profile', 'my_show_extra_profile_fields' );

function my_show_extra_profile_fields( $user ) { ?>
  <table>
  <tr>
    <?php

    $gender = get_user_meta( $user->ID, 'gender', true );
     ?>
			<th><label for="gender">gender</label></th>

			<td>
				 <input type="radio" name="gender" id="gender" <?php  checked( $gender, 'male' ); ?> value="male" >male
  				<input type="radio" name="gender" id="gender" <?php  checked( $gender, 'female' ); ?>value="female">female<br>
				<span class="description">Please enter your gender</span>
			</td>
  </tr>
  </table>
  <?php }

  function my_save_extra_profile_fields( $user_id ) {

	if ( !current_user_can( 'edit_user', $user_id ) )
		return false;
    update_usermeta( $user_id, 'gender', $_POST['gender'] );
    }