The short answer:
- The Guinea 'No' vote: Sekou Toure, who was by far the most influential figure in Guinea, campaigned for a 'no' vote.
- Others voting 'Yes': Almost all local political leaders had benefited from French patronage and thus tended not to favour a radical change in the relationship between France and the colonies.
Many of the African political leaders who emerged in the 1940s & 1950s (e.g. Felix Houphouet-Boigny in Cote d'Ivoire and Sekou Toure in Guinea) were charismatic figures who were seen to stand up to the colonial powers on issues of vital concern to the local populations.
Africans identified with their political leaders as leaders
of their territories. Indeed, as founders of the first mass political parties
in their territories, leaders such as Houphouët-Boigny, Senghor and
Touré symbolized the nation for many party members and sympathizers,
and indeed for the wider electorate.
(T. Chafer, 'The End of Empire in French West Africa')
At the same time, from 1950 onwards (at least in West Africa), the French administration worked hard to co-opt the local elites:
These measures included banning the familiar 'tu' habitually used by
Europeans when addressing blacks, inviting prominent Africans as a
matter of course to official and private ceremonies, liberally
awarding study grants, and systematically recruiting young people with
secondary and higher education for local positions of responsibility
in French Equatorial Africa. As a result, when the basic law was
passed in 1956, the African élites enthusiastically accepted political
autonomy but without any hostility towards France and without any
desire to break the structural relationship with the former colonial
(U N E S C O General History of Africa, vol VIII)
For the most part,
...nationalist movements developed slowly in French West Africa, in
contrast with the British colonies. This was because the openings of
the post-World War II era brought the African political elite into a
close-knit relationship with France. A handful of them served in
French cabinets in the period of decolonization.
This 'close-knit relationship' was to prove the key to France maintaining a high degree of economic and even political control on most of the Francophone countries after independence was achieved (mostly in 1960), a situation which has featured prominently in the literature on neo-colonialism (by no means the just preserve of left-wing academics).
Percentage of 'Yes' votes in the 1958 Referendum in French West Africa by territory. Map source: http://4.bp.blogspot.com/-HP0_A7xd6M8/U0ub7ODsJuI/AAAAAAAAAeo/RMTCY5N0lXg/s1600/FRENCH+WEST+AFRICA.jpg (edited). Data source: various Wikipedia articles.
Sekou Toure actually favoured a union of former French colonies but he saw French involvement in African affairs (as per the 1958 constitution) as exploitative.
Before the referendum in
September 1958 he stated, ‘We prefer poverty in freedom to riches in slavery’
(H. Adi & M. Sherwood, 'Pan-African History')
His highly successful involvement in union activities from the mid 1940s made him popular with workers (but unpopular with the French authorities) and ultimately enabled him to persuade union leaders to back a 'no' vote in Guinea. An adept politician, Toure used his name to increase his popularity by claiming to be a descendant of the Muslim warlord and cleric Samori Toure who had resisted the French colonial advance for some 16 years in the late 19th century. He also recognized that, if the nationalist movement was to win,
it needed to broaden
its appeal beyond its largely urban and trade union bases into the rural
areas, which were the main electoral power base of Africa’s political
leaders. This was the US-RDA’s strategy in Soudan and it was also Sekou
Touré’s strategy in Guinea, where he used the trade union movement as
a base from which to construct a wider anti-colonial front...
(T. Chafer, 'The End of Empire in French West Africa')
Drawing on the prominence of Islam in Guinea,
Sékou Touré unified the region’s diverse ethnic groups
with an unspoken promise of making Guinea an Islamic
state (which, ultimately, he did not do). By advocating a
greater role for African women in public office and a redistribution
of land, Sékou Touré appealed to peasants,
women, and youth
(W.Page & R. Hunt Davis, 'Encyclopedia of African History and Culture, vol. 4')
In 1957, just a year before the vote, Sekou Toure's party won 56 of the 60 seats in the territorial assembly. He was thus by far the most influential figure in Guinea and, like Houphouet-Boigny in Cote d'Ivoire, successfully used his influence to sway the vote in the direction he wanted, though in the opposite direction to Houphouet-Boigny. The overwhelming 'yes' vote in Cote d'Ivoire was largely due to the influence of Felix Houphouet-Boigny, champion of peasants and small planters. In fact, Houphouet-Boigny was so idolized by most Ivorians that, even when the Ivorian economy faltered badly some 30 years later, he was still widely popular.
In Niger, the situation was different - there was no one single dominant figure at the time, and the two most prominent local politicians were publicly divided. The leader of the 'No' movement, Djibo Bakary, lacked the influence and political acumen of Sekou Toure, and was undermined by his anti-tribal chiefs policy. Hugely influential at the grassroots level, the chiefs unsurprisingly opposed him and urged a 'Yes' vote. The French government, concerned about the potential threat of an unfriendly political leader in a country which bordered Algeria, also worked hard to bring about a result favourable to their interests.
As a footnote, the change from colony to independent country was not easy for Guinea. Although Sekou Toure's policies were at least partly at fault, the French reaction to the 'No' vote was ruthless. As African Heritage notes,
It was seen as a treason and an affront… and France never forgave
Guinea, destroying files when leaving, withdrawing abruptly,
destroying infrastructures, and breaking political and economic ties.
Actually, France and Guinea have since reconciled to a great extent, but at the time the French delivered a harsh message, one which other Francophone countries were well aware (before the referendum) that they would have received had they also voted 'No'.
T.O'Toole & I.Bah-Lalya, 'Historical Dictionary of Guinea'
W.Page & R. Hunt Davis, 'Encyclopedia of African History and Culture, vol. 4'
T.Chafer, 'The End of Empire in French West Africa'
J.Abbink, M. de Bruijin & K. van Walraven, 'Rethinking Resistance: Revolt and Violence in African History'
H. Adi & M. Sherwood, 'Pan-African History'
P. Anyang' Nyong'o, 'The Development of Agrarian Capitalist Classes in Ivory Coast, 1945-1975'. In P.Lubeck (ed.), 'The African Bourgeiosie'
J. Cartwright, 'Political Leadership in Africa'
U N E S C O General History of Africa, vol VIII