In the photograph, two very young girls are sitting next to each other on a sofa. One is going on four and the other a toddler less than two years of age. The older one, while sucking on her milk bottle is trying to pull the bottle from the younger one’s mouth. The younger one is turning her head in an attempt to avoid losing her bottle. She is also reaching for it to protect it while pushing the older one away with her other hand. You think you are looking at a harmless bout between two young children. But if that is the case then why would anyone bother to take such a picture? What are the odds of capturing such an abrupt and passing attempt to snatch possession of one by the other on film?

Take a closer look at the younger girl’s face; it is very calm, its dreamy expression is showing no signs of anxiety. The eye which is visible is wide open, not squinting as one would expect had she been jerking her head away. The older girl’s hand is not grasping the younger one’s bottle. The hand is gently supporting the tip of the bottle with four fingers. The thumb is stabilizing the bottle from one side while three fingers are touching it from the other. Her pinky is hanging free, not what you would expect from a quick snatching movement which would have engaged all five fingers. The toddler’s hand lacks the tension that would have been part of a hasty attempt to save what is hers. In fact it seems like her hand has just let go of the bottle and it is slowly drifting towards her exposed belly button, while the older girl continues to support it.

If you look closely at the ‘bottles’ you see that they are not bottles at all. They are dispensers made of hardened plastic tubes which hold disposable plastic bags. These plastic bags are open on one side. The flaps of the open end are folded over the top of the plastic cylinder and held in place by a plastic ring which is screwed over the top fastening a rubber nipple from which the child can suckle. The nice thing about the ‘milk bag’ is that an experienced child can use vacuum rather than gravity in order to drink its content. When the technique is mastered a child can drink while the bottle hangs from its mouth, drinking as an afterthought with two hands free to entertain other activities.

The picture shows a unique symbiosis between two sisters, a yet-to-be-classified evolutionary adaptation to the socializing-while-feeding possibilities created by the introduction of the ‘milk dispenser’. The two girls have developed a mutually beneficial ‘lend limb’ program. The older one enjoys the comfort of a ‘thumb’ which is not her own while she suckles on her bottle. This is a dependency she developed when she was nursing from her mother. This was a way of clutching on with more than just her mouth; a reminiscent form of clinging which has faded away in humans but is so common farther back in our evolutionary chain. When the time came the bottle substituted the mother, but she was forever destined to forage for a thumb whenever she wanted to make the most of the divinity of the nursing experience.

The younger one, seeing the downside of thumb foraging, did not develop an extra-bodily dependency. Since the dawn of her existence she decided to keep things ‘close to home’ and avoid anything which even remotely resembles foraging and gathering. She has therefore relied on her own belly button for a complementary soothing purpose. This approach made things easier for her given that her belly button was always with her. Anything else she needed she could make happen with a shriek.

When they drink together as they are doing in the picture they have two mouths to feed and four hands to work with. Two hands have to be allocated to satisfy the ‘thumb’ needs of the older one, leaving each with one free hand. Since the younger one needs her hand for her belly button, she has no hands left to adjust her own milk bottle; hence the older one lends her remaining hand for the job, since it is she who needs the younger one’s other hand for its precious thumb. She is old enough to hold on to a bottle with no hands, thus they achieve a perfect harmony. Once the mathematics of adding and subtracting limbs from each other is done, the girls can enjoy their mutual company and interact with their environment as they see fit. In this case they are enjoying a post-bathing-pre-bedtime drink in the living room in front of the television.

The picture shows that the older girl has mastered the technique of holding the milk dispenser with her mouth. The younger one is still learning. The older girl’s mastery is made evident by her body posture. She is seated in a more comfortable position. Her body is turned sideways facing the television, her left side propped against the back of the sofa and her knees tucked backwards for comfort and support. Her younger sister cannot face the television because such a posture would deprive her older sister of free access to her mouth. She is seated in a sprawled position typical of youngsters who are ‘clinically asleep’[1]with her body facing the camera. Her head is turned as far left as it can go without losing the nipple. Her eyes are looking further to her left towards the television. She can get to see some of the program thanks to the flexibility of her neck, the softness of the rubber nipple and the range of her angular vision. The television program is just a backdrop for their shared experience. They have each other and that’s all that matters.

As you can see – sometimes it is the picture that deserves a thousand words.