I came upon this study and I think you guys might find it interesting. (Note that this study was of youth at a baptist conference, so I'm not surprised by the correlation between infant baptism and reduced church attendance.)
"The theological framework posed the question regarding the efficacy of baptism. It was suggested that, if baptism is conceptualized as a special dispensation of divine grace, and if divine grace is conceptualized as promoting a positive relationship between creator and creature reflected in nurturing visible spirituality and spiritual practices, then among the highly committed a higher level of spiritual practices would be seen among the baptised. This suggestion was formulated in the conventional style of a negative hypothesis, namely that there is no association between baptismal status and spiritual practice. The data did not support this negative hypothesis. The data reveal that the young people who had not been baptised reported lower levels of spiritual practices across all three measures included in this study: church attendance, personal Bible reading, and personal prayer. Moreover, those who had been baptised as infants (prior to being able to make a personal confession of faith according to the normative practice within the Baptist tradition) showed no difference when compared with those who had been baptised as an older child or adolescent in the reported levels of Bible reading and personal prayer. However, those baptised as infants reported significantly lower levels of church attendance compared to those who had been baptised later in life. According to these data infant baptism may be seen to be almost as efficacious as adult baptism, but not quite as efficacious. This empirical evidence may suggest that Baptist theologians may wish to revisit the generally-held view that Baptism is merely a public acknowledgment of one’s confession of faith and repentance from sin and consider that the act of Baptism may contain a previously unacknowledged dispensation of grace."
"The theological framework posed the question regarding the efficacy of baptism. It was suggested that, if baptism is conceptualized as a special dispensation of divine grace, and if divine grace is conceptualized as promoting a positive relationship between creator and creature reflected in nurturing visible spirituality and spiritual practices, then among the highly committed a higher level of spiritual practices would be seen among the baptised. This suggestion was formulated in the conventional style of a negative hypothesis, namely that there is no association between baptismal status and spiritual practice. The data did not support this negative hypothesis. The data reveal that the young people who had not been baptised reported lower levels of spiritual practices across all three measures included in this study: church attendance, personal Bible reading, and personal prayer. Moreover, those who had been baptised as infants (prior to being able to make a personal confession of faith according to the normative practice within the Baptist tradition) showed no difference when compared with those who had been baptised as an older child or adolescent in the reported levels of Bible reading and personal prayer. However, those baptised as infants reported significantly lower levels of church attendance compared to those who had been baptised later in life. According to these data infant baptism may be seen to be almost as efficacious as adult baptism, but not quite as efficacious. This empirical evidence may suggest that Baptist theologians may wish to revisit the generally-held view that Baptism is merely a public acknowledgment of one’s confession of faith and repentance from sin and consider that the act of Baptism may contain a previously unacknowledged dispensation of grace."