According to a 2008 research conducted by the universities of Pennsylvania and Taiwan it seems that our beloved akitas are the most aggressive towards other dogs.

It's although very interesting that the research doesn't mention any hierarchical social structures, leaders of the pack, dominance etc. On the contrary, they mention the purpose that each breed was bred for. This comes to no surprise for us, since humans have used dogs for thousands of years against other animals, dogs (in dog fighting) and even against other humans.  

			‘‘Snaps, bites or attempts to bite’’
	n	Stranger	%	Owner	%	Dog	%	Rivalry	%
Akita	99	3	(3.00)	1	(1.00)	29	(29.30)	5	(7.10)
Pit Bull	132	9	(6.80)	3	(2.30)	29	(22.00)	11	(11.50)
Jack Russell Terrier	78	6	(7.70)	3	(3.80)	17	(21.80)	7	(11.10)
Australian Cattle Dog	136	13	(9.60)	2	(1.50)	28	(20.60)	5	(4.90)
Chihuahua	56	9	(16.10)	3	(5.40)	10	(17.90)	2	(4.80)
Dachshund	68	14	(20.60)	4	(5.90)	12	(17.60)	5	(8.80)
English Springer Spaniel	57	2	(3.50)	2	(3.50)	10	(17.50)	4	(9.50)
German Shepherd	292	13	(4.50)	6	(2.10)	48	(16.40)	13	(5.80)
Soft Coated Wheaten Terrier	216	9	(4.20)	4	(1.90)	35	(16.20)	9	(5.20)
Boxer	70	4	(5.70)	0	0.00	11	(15.70)	3	(5.30)
Australian Shepherd	177	11	(6.20)	1	(0.60)	26	(14.70)	10	(6.50)
Border Collie	163	13	(8.00)	3	(1.80)	22	(13.50)	7	(5.10)
Doberman Pinscher	144	8	(5.60)	2	(1.40)	16	(11.10)	4	(3.40)
Beagle	63	5	(7.90)	5	(7.90)	6	(9.50)	4	(8.00)
Great Dane	53	3	(5.70)	1	(1.90)	5	(9.40)	2	(4.90)
Airedale Terrier	66	3	(4.50)	1	(1.50)	6	(9.10)	2	(3.60)
Poodle	169	2	(1.20)	0	0.00	13	(7.70)	2	(1.40)
Rottweiler	210	10	(4.80)	2	(1.00)	16	(7.60)	2	(1.10)
Cocker Spaniel (American)	107	5	(4.70)	6	(5.60)	8	(7.50)	4	(5.20)
Golden Retriever	181	2	(1.10)	1	(0.60)	13	(7.20)	3	(2.00)
Collie	132	2	(1.50)	3	(2.30)	9	(6.80)	2	(1.60)
Portuguese Water Dog	75	2	(2.70)	0	0.00	5	(6.70)	2	(3.30)
Mastiff (English)	126	3	(2.40)	1	(0.80)	8	(6.30)	5	(4.70)
Rhodesian Ridgeback	69	1	(1.40)	0	0.00	4	(5.80)	1	(1.70)
Siberian Husky	54	0	0.00	1	(1.90)	3	(5.60)	1	(2.10)
Bichon Frise	65	3	(4.60)	1	(1.50)	3	(4.60)	2	(4.20)
Bernese Mountain Dog	67	1	(1.50)	2	(3.00)	3	(4.50)	1	(1.60)
Brittany Spaniel	66	0	0.00	1	(1.50)	3	(4.50)	1	(2.00)
Labrador Retriever	349	8	(2.30)	6	(1.70)	15	(4.30)	6	(2.20)
Havanese	73	2	(2.70)	0	0.00	3	(4.10)	1	(1.80)
Shetland Sheepdog	57	2	(3.50)	2	(3.50)	2	(3.50)	2	(3.80)
Whippet	59	0	0.00	1	(1.70)	2	(3.40)	1	(1.90)
Greyhound	62	1	(1.60)	0	0.00	1	(1.60)	0	0.00

 

The research concludes that besides the hereditary reasons an important role in aggresiveness plays the environment. They also mention that these results cannot be used as criteria to prevent attacks from any breed.

The research PDF can be found here

Photo by jorunngro