Interactional properties are prominent among the kinds of properties that count in determining sufficient family resemblance

"Interactional properties are prominent among the kinds of properties that count in determining sufficient family resemblance. Chairs share with stools and other kinds of seats the PURPOSIVE property of allowing us to sit. But the range of MOTOR ACTIVITIES permitted by chairs is usually different from stools and other seats. Thus the interactional properties relevant to our comprehension of chairs will include perceptual properties (the way they look, feel, etc.), functional properties (allowing us to sit), motor-activity properties (what we do with our bodies in getting in and out of them and while we're in them), and purposive properties (relaxing, eating, writing letters, etc.)." (#60 2142)