Physical Growth
At this stage, an infant's hands are more developed than their legs or feet, a phenomenon called cephalocaudal development. Feet appear flat as the arch hasn't yet developed.
Cephalocaudal principle
The anterior fontanelle, a gap in the skull bones found in infants, begins to close; the posterior fontanelle has already closed off completely at this stage.
Infants develop more teeth; more incisors appear, followed by molars. Infants can now eat certain solid foods that can be gummed, like soft pieces of fruits, well cooked vegetables, and tofu.
Upper central incisors appear during the eight month while the lateral incisors appear between 10th-12th months. Infants will have 1-8 teeth in this period.
While legs may continue to appear bowed, hands appear larger and out of proportion compared to the rest of the body. The minimum weight of infants must be at least 9 kilograms; the body weight must triple by the infant's first birthday. The rate of weight gain is nearly 500 grams per month. The infant's height must be a minimum of 69 centimeters, having become 1.5 times the length at birth. The head and chest circumference continue to remain equal; baby fat continues to appear in neck, thighs and arms. Both eyes begin to work in unison, i.e. true binocular coordination is achieved.
Reflexes
Upon pricking the infant's foot, softly, with a sharp object, the infant withdraws its foot. This reflex disappears during the eighth month.
The parachute reflex appears during the ninth month, where upon the infant extends its arm if his body is rotated face forward, after being in the upright position, to protect self from falling.
Plantar reflex is a reflex seen when the foot is stimulated with a blunt object. In older children, this reflex is executed by the toes curving down and inwards, withdrawing from the object (Flexor). However, in infants, toes fan out (Extensor). Thus, when an infant is aged 9-12 months the reflex changes from extensor to flexor.
Infants have an inbuilt neck righting reflex, where infants correct the orientation of the body with respect to the neck. To put it simply, if an infant's neck is rotated, the body will also rotate in that direction. This reflex will vanish too, during the 9th-12th month.
Motor Skills
Infants, during their ninth month, have a regulated bowel and bladder systems. This is also the stage when infants begin to crawl, with the high chances of being able to pull themselves up with support.
Infants begin to avoid obstacles by sidestepping, during their 9th-12th month. It is also possible to walk with adult support; some infants can walk without any support as well.
Infants can also sit for prolonged periods of time, strongly with no support. Their balance is better, and they can shift easily without falling. They can now crawl up and down the stairs, while being able to creep on their hands and knees.
Infants develop a pincer grip, i.e. holding objects between their thumbs and forefingers. They begin to explore objects, by poking them or transferring them from one hand to another. They are now capable of stacking objects, one on top of another.
They can place objects, sorting them into different shapes, into appropriate containers.
Infants during this stage can respond to hearing tests. However, due to a smaller attention span, the testing may not be effective. They can pay increasing attention to speech.
During the ninth month, infants may begin to favor one hand over the other, doing majority of tasks with it.
• Infants may begin to imitate scribbling, being able to hold a pencil properly.
• Infants also develop basic language, saying simple two syllable words.
• Infants also develop the ability of being able to finger feed themselves.
• Infants also begin to show their assertiveness, shouting at the caregiver when they disagree or dislike a particular thing.
• Infants can also turn pages of books, but many at a time.
Besides the development of motor skills, this is also the beginning of cognitive development.
Cognitive development is the ability to think reason and solve problems, appropriate for their age. Infants begin showing curiosity, exploring objects by virtue of their newfound ability to move and crawl.
They are also able to recognize objects in reverse; they can reach out for objects that are out of their reach but visible. They may intentionally drop objects, and observe objects that capture their interest. They also develop preference towards a particular toy.
Infants develop object permanence, i.e. they can now find hidden objects easily. They may grow apprehensive of strangers, and cry when their parents leave. This indicates the development of the power of recognition in infants, and, they also develop cooperation at this stage, helping the parent in dressing up by raising their arms or staying still.
Object permanence
Infant's basic body language also tends to get more and more developed. Though unable to speak, they may shake their heads "yes" or "no" and recognize and respond to your basic gesture, correspondingly.
As the infant reaches his first birthday, he learns how to use objects correctly, learning to imitate through observation. They can also recognize objects, capable of pointing at the object when its name is called out. By the 12th month, infants will know what an object is used for; while a 9 month old may not know how to use the phone, a 12 month old will make calls, imitating the parent using the phone. This signifies the ability to perceive and replicate.
Cognitive skills can be aided in development through exercises stimulating the mind. Providing the infant with simple puzzles to solve will keep the infant occupied, honing their mental skills.
While separation anxiety at this stage may become severe, guardians may use transitional objects to help infants relax.
It is recommended to consult a doctor if your infant hasn't reached a majority of these milestones.
