First-born Son - father's father
Second-born Son - mother's father
Third-born Son - father
Fourth-born Son - father's eldest brother
Fifth-born Son - father's 2nd oldest brother or mother's oldest brother

Females

First-born Daughter - mother's mother
Second-born Daughter - father's mother
Third-born Daughter - mother
Fourth-born Daughter - mother's eldest sister
Fifth-born Daughter - mother's 2nd oldest sister or father's oldest sister

 
An understanding of naming patterns can be very helpful in tracing ones ancestry. Many Scotts families follow the custom of naming their children after the grandparents in the following manner: 

First born son named for the paternal grandfather.
Second son named for the maternal grandfather.
Third son named for the father.

First born daughter for the paternal grandmother. (sometimes maternal grandmother)
Second daughter for the maternal grandmother. (sometimes paternal grandmother)
Third daughter for the mother.

This can cause families to have two children with the same name if the grandparents had the same  name. The process also started over if the parent remarried, so it is common to find half brothers or sisters with the same names. Not all Scotts families followed this pattern, but many that did continued it  long after leaving Scotland.

 
Patronymics - Lowland names such as Wilson, Robertson, Thomson and Johnson are among the most common surnames in Scotland. 'Mac' names are also patronymic. MacManus - son of Magnus. 'Mc' is just a printer's contraction and has no significance as to etymology.

Occupation - Names which are derived from trades and occupations - mostly found in towns. The most common of these is Smith (the most common surname in Scotland, England and the USA) but other examples would be Taylor (tailor) Baxter (baker) and Cooper (barrel maker).

Locality - In Scotland the tendency is for people to be named after places (in England the tendency is the opposite). Examples of such names are Morton, Lauder, Menzies and Galloway.

Nickname - Names which could refer to color or size, e.g. White, Black, Small, Little. Scottish names in this category include Campbell (meaning 'crooked mouth'). Another example of nickname - this time referring to the bearers origins - is Scott.

New England's first settlers bore names of three different types: those of English origin, those of  Hebrew derivation, and those intended to have a moral significance. Early settlers seemed to favor names for their associated moral qualities. Among girls' names, which  were no doubt intended to incite their bearers to lead godly lives, were: Content, Lowly, Mindwell, Obedience, Patience, Silence, Charity, Mercy, Comfort, Delight and Thankful.   Many different practices of naming were used among the early colonists.   A popular custom in both Virginia and New England was the use of surnames as given names. This occurred mostly with boys, but it was not unknown for girls. Some names were also chosen for their  magical properties, and astrologers were consulted in attempt to find a "fortunate" or "lucky" name.   Among Quakers in Colonial Pennsylvania and Delaware, babies went through a ritual called nomination. An infant's name was carefully selected by the parents, certified by friends, witnessed by  neighbors, and then entered in the register of the meeting. Basically new practices were developed within each region or culture as America was settled. Old English names, connected with the Church of England, were not often favored by the Puritans.   Puritans named their children somewhat differently than other English-speaking settlers, preferring  Biblical names. Evidently, some parents shut their eyes, opened the Bible, and pointed to a word at  random--what else could account for a child being named Notwithstanding or Maybe? 
Our ancestors often used the following naming pattern when selecting a name for a new child. This explains why certain names are very common in a family line. Watching for these patterns can help in your genealogy research. 

     Naming pattern:

     1st son = father’s father
     2nd son = mother’s father
     3rd son = father
     4th son = father’s oldest brother
     5th son = father’s second oldest brother or mother’s eldest brother

     1st daughter = mother’s mother
     2nd daughter = father’s mother
     3rd daughter = mother
     4th daughter = mother’s oldest sister
     5th daughter = mother’s second oldest sister or father’s oldest sister

     It is also common to use:
     the mother’s maiden name as a second name;
     the surname of close friends as a second name;
    give another child exactly the same name as a previous child who had died; 
    or give a child the name of a relative or friend who had recently died.