I'll preface this with I am offering my thoughts for clarity (hopefully), but if in doubt ask Dr. Horowitz directly (contact info is included in a link from her contribution piece). Academically temperament is generally used as "Individual differences in behavior resulting from genetics. Seen at birth." and personality is generally used as "The resulting outcome of both genetics and life experience." Patricia McConnell likens temperament to the canvas and personality as the painting.
While most breed standards do use the word temperament, I'd argue perhaps personality is a more accurate word to use. Certainly by the age a dog is eligible to be shown, and even more so by social maturity, the waters can be pretty muddied as to what what degree nature and nurture contributed to most behavioral traits .
Sara Ruesche wrote a fantastic post called "It's all in how they're raised!" complete with super helpful graphics
http://paws4udogs.wordpress.com/2012/12/10/its-all-in-how-theyre-raised/
I shared the proceedings from the Eukanuba Breeder Symposium previously, but "Creating Behaviorally Stable Dogs: The Breeder’s Role by Margaret M. Duxbury, DVM, DACVB has good information on the heritability of behavior. The post is at:
http://www.newf.net/Forums/showthread.php?t=103404 but I'd be happy to email a .pdf if anyone has trouble downloading it directly.
I've included an excerpt below written by Lore Haug, DVM, MS, DACVB titled "Treat or euthanize? Helping owners make critical decisions regarding pets with behavior problems" the full article is available at:
http://veterinarymedicine.dvm360.com/vetmed/article/articleDetail.jsp?id=748339&pageID=1&sk=&date=
Genetics
Genetic and environmental influences are intricately intertwined. Research in a variety of species and a variety of fields shows genetic expression can be altered with environmental experience8-10 ; however, the animal's genetic template is set and will influence the types of behaviors expressed as well as the approach to resolving them. Pets that have various types of developmental or genetic disorders (e.g. deafness, impulse control disorders) often have a poorer prognosis because the rehabilitation process can be longer and more arduous. In my experience, working with animals with such disabilities often requires a higher skill level on the part of the owner and assistance from a more educated behavior professional.
Developmental period
The pet's developmental period, especially the socialization experience, is a key influence on future behavior.11-13 Certain training during this time can greatly reduce the likelihood of behavior problems; other training practices will induce or worsen certain behavior issues. Training and puppy raising methods that emphasize "dominance theories" and confrontational techniques damage the owner-pet relationship and can increase biting and aggressive responses toward owners.14,15 I have seen a number of dogs develop noise phobia and fear of people in direct response to the training philosophy of one currently popular training franchise. This method involves yelling at the dog and throwing chains in the dog's direction to startle or scare the dog into stopping the undesirable behavior.
As with people, developmental changes during an animal's juvenile and adolescent period have a notable impact on the animal's interaction with its environment and, thus, its behavior. This period is the most trying time when raising a pet and a time when most owners reach the limits of their knowledge and fall short of their obligations as responsible pet owners. Poorly socialized pets may pose a greater challenge for rehabilitation.
8. Francis D, Diorio J, Liu D, et al. Nongenomic transmission across generations of maternal behavior and stress responses in the rat. Science 1999;286(5442):1155-1158.
9. Swanson KS. Nutrient-gene interactions and their role in complex diseases in dogs. J Am Vet Med Assoc 2006;228(10):1513-1520.
10. Seso-Simic D, Sedmak G, Hof P, et al. Recent advances in the neurobiology of attachment behavior. Transl Neurosci 2010;1(2):148-159.
11. Appleby D, Bradshaw JW, Casey RA. Relationship between aggressive and avoidance behaviour by dogs and their experience in the first six months of life. Vet Rec 2002;150:434-438.
12. Pierantoni L, Verga M. Behavioral consequences of premature maternal separation and lack of stimulation during the socialization period in dogs. J Vet Behav 2007;2(3):84-85.
13. Seksel K, Mazurski EJ, Taylor A. Puppy socialization programs: short and long term behavioral effects. Appl Anim Behav Sci 1999;62(4):335-349.