Though it is likely that a person who had a secure attachment as a child will adjust well later in life, it is not always the case. The time of development between infant and adulthood has the opportunity to change the person; for example, if the person goes through some kind of traumatic event like bullying or a death. These kind of events may change the person for the worse even if he/she had a secure attachment as a child. Alternatively, if a person does not have a secure attachment as a child does not determine a bad adjustment later in life. People can go through the same events and grow postively from them, become more confident, stronger.
This is very true. However, there are always exceptions to the rule, and at least from the textbook, it seems like secure attachment usually does tend to correlate with positive attributes later in life. Traumatic events are not common, and could be the exception to the rule (or one exception, anyway). I do agree, however, that environment could potentially play a role in creating secure attachment and the same factors could help with positive attributes later in life, meaning that secure attachment does not cause these positive attributes, but rather they are caused by the same or similar things.
