Baby Development and Growth

I need help answering these questions attached. I'm having difficulty providing short responses to them.

1. Table 3.6 states that between 6-9 months babbling, including both consonant and vowel sounds, are repeated in syllables.

10-12 months- comprehension of simple words; speech-like intonations, specific vocalizations that have meaning to those who know the infant well. on page 112.

Now, does using baby talk to an infant for those few months have a positive effect or negative effect on an infant's capability to learn proper words just months later? Should we talk to infants in more of a formal way?

2. On pg. 86, Berger states that, "the average infant weighs about 7.5lbs., and are about 20 in., and will normally double by the fourth month, triple by the age of 1, and quadruple by the age of 2". Berger also states that " by the age of two humans grow almost a foot and most are half their adult height" (p. 86).

This is a weight I haven't seen a baby born at AT ALL, they're either smaller or larger than the average or "normal" birth weight. What are your thoughts and attitudes towards babies who aren't born within average birth weight? Do you feel they're too small/big? Normal/abnormal? What do you feel is a healthy birth weight for babies? What do you think some of the challenges may be giving birth to a baby smaller or much larger than the average, if any?

3. On page 124-125 in the text infants and their emotions are discussed. The text mentions that smiling and laughing, anger and sadness and fear are all the prime emotions that infants feel. Stranger wariness and separation anxiety is something that everyone can relate to. What do you think the outcomes and experiences with stranger wariness and separation anxiety has on an infant and how will that impact them later as an adult?

4. According to the text book on page 130, studies of how and when to begin toilet training have changed over the century. Potty training started as early as a month old, to now waiting for the child to decide when.
Why has there been such a change in the approach to when to begin potty training? Can potty training to early or to late be harmful to the psychological development of a child?

5. On page 103 in our book it describes co-sleeping as a practice in which infants sleep in the same bed as their parents. The book also talks about how co-sleeping encourages breast-feeding as said by pediatricians and that some pediatricians advise against co-sleeping. When my daughter was an infant she slept in her crib but now she is 4 and goes from my bed to her bed. Some children have fears and feel safe to sleep with their parents. As for infants we may not feel them as we are sleeping although some parents may set up some guard to know that their child is in the bed with them. Do you think co-sleeping is a good practice?

6. Social deprivation in children can have lasting effects on brain growth. Children who are isolated or have little or no sensory stimulation have harmful effects on their brain. In our textbook (pg. 92), the study of Romanian children socially deprived in orphanages "show signs of emotional damage." The children "were too friendly to strangers, too angry without reason or too frightened of normal events." The children in Romanian orphanages "tend to have smaller brains than other children and they have lower IQs than average. According
to this article published http://www.thecrimson.com/article/2011/11/9/hms-prof-brain/ on a study performed by Harvard Medical School Professor, Charles A. Nelson.

Socially deprived children and all people need love, attention and stimulation. Being socially stable helps the child express feelings, develop friendships and helps them feel confident. As an adult we crave social stimulation in much the same way that children need it to grow and develop. How can we promote a stimulating environment for infants and children? What can orphanages do differently to stop social deprivation for the children living there?