The 5% figure is not quite right. Certainly it is difficult to be sure what the actual percentage was but let's look at it a bit more at some studies on this:
Lowell Bennion concluded 20%-40% of mormon families were polygamous.
Stanley S. Ivins study came up with 15%-20% of mormon families in UT as polygamous.
Arrington and Bitton claimed 5% of males, 12% females, and 10% children were from polygamous households.
The percentages said to be as low as 3% are usually taken from the Reed Smoot hearings and are questionable.
Church Leaders encouraged polygamy. It was even taught as essential to salvation. It was the "new and everlasting covenant" and church leaders refused for a long time to give in to pressure to change that. It was taught that polygamy wasn't going to go away ever. Here are some quotes:
"We are not going to stop the practice of plural marriage until the Coming of the Son of Man." – President Wilford Woodruff (Manti Temple dedication - 17 May 1888)
"If we were to do away with polygamy, it would only be one feather in the bird, one ordinance in the Church and kingdom. Do away with that, then we must do away with prophets and Apostles, with revelation and the gifts and graces of the Gospel, and finally give up our religion altogether and turn sectarians and do as the world does, then all would be right. We just can't do that, for God has commanded us to build up His kingdom and to bear our testimony to the nations of the earth, and we are going to do it, come life or come death. He has told us to do thus, and we shall obey Him in days to come as we have in days past" (Journal of Discourses 13:165 - p.166).
"Now if any of you will deny the plurality of wives, and continue to do so, I promise that you will be damned" -Brigham Young (published in the church owned Deseret News, November 14, 1855)
"Some people have supposed that the doctrine of plural marriage was a sort of superfluity, or non-essential, to the salvation or exaltation of mankind. In other words, some of the Saints have said, and believe, that a man with one wife, sealed to him by the authority of the Priesthood for time and eternity, will receive an exaltation as great and glorious, if he is faithful, as he possibly could with more than one. I want here to enter my solemn protest against this idea, for I know it is false." (Journal of Discourses, Vol.20, p.28 - p.29, Joseph F. Smith, July 7, 1878)
"The only men who become Gods, even the Sons of God, are those who enter into polygamy. Others attain unto a glory and may even be permitted to come into the presence of the Father and the Son; but they cannot reign as kings in glory, because they had blessings offered unto them, and they refused to accept them." (Journal of Discourses, Vol.11, p.268 - p.269, Brigham Young, August 19, 1866)
One of the most interesting things is a revelation from god to LDS President John Taylor. It was written in his own journal and appears very much to be a real revelation on polygamy. This revelation is not canonized by the LDS church but a copy of it is contained in their archives.
"My Son John. You have asked me concerning the New and Everlasting Covenant and how far it is binding upon my people;
Thus saith the Lord: All commandments that I give must be obeyed by those calling themselves by my name, unless they are revoked by me or by my authority, and how can I revoke an everlasting covenant; for I the Lord am everlasting and my everlasting covenants cannot be abrogated nor done away with, but they stand forever.
Have I not given my word in great plainness on this subject? Yet have not great numbers of my people been negligent in the observance of my laws and the keeping of my commandment and yet have I borne with them these many years and this because of their weakness, because of the perilous times,
And furthermore, it is more pleasing to me that men should use their free agency in regards to these matters. Nevertheless, I the Lord do not change and my word and my covenants and my law do not.
And as I have heretofore said by my servant Joseph: All those who would enter into my glory must and shall obey my law. And have I not commanded men that if they were Abraham's seed and would enter into my glory, they must do the works of Abraham?
I have not revoked this law, nor will I, for it is everlasting, and those who will enter into my glory must obey the conditions thereof; Even so Amen." (John Taylor 27 September 1886 Revelation)
Did Polygamous relationships involve sex? Was Joseph Smith's polygamy different?
It wasn't the only reason for Joe's marriages but to me it seems obvious that the sexual dimension of the relationship is an aspect that joseph wanted. The relationships tended to have certain goals often in mind.
-They were used to build bonds between joseph and his elite circle.
-They were used as "exchanges" as well. in more than one case Joseph traded one sealing for another. He would seal a man and woman who wished to marry for eternity in exchange for a daughter, sister, or cousin.
-They were because joseph wanted to marry the girls and/or was commanded by god. On many occasions joseph is quoted as saying to family members that he was quite taken with their daughter/sister/cousin and wanted to take her as a wife. Whether it was because Joseph wanted them for sex or "god" wanted joe to take them for sex, the marriage still involved a physical/sexual relationship.
The word "marriage" for mormons has a lot to do with sex. Marriage is an important institution that mormons must enter into before they are aloud to have sexual relations with their partner.
After god supposedly married Adam and Eve he commanded them "And I, God, blessed them, and said unto them: Be fruitful, and multiply, and replenish the earth, and subdue it, and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth." (Moses 2:28)
"AND now I would that ye might know, that after my father, Lehi, had made an end of prophesying concerning his seed, it came to pass that the Lord spake unto him again, saying that it was not meet for him, Lehi, that he should take his family into the wilderness alone; but that his sons should take daughters to wife, that they might raise up seed unto the Lord in the land of promise." (Nephi 7:1)
"...and they shall pass by the angels, and the gods, which are set there, to their exaltation and glory in all things, as hath been sealed upon their heads, which glory shall be a fulness and a continuation of the seeds forever and ever." (D&C 132:19)
As an LDS girl growing up I was taught over and over again that the purpose of marriage was to bring up righteous children. I was taught that sex was not right until after marriage. Sex and marriage went together.
How do Mormons feel about polygamy now?
Mormons now pretty much hate polygamy. I find that absolutely fascinating! The conditioning of church leaders has now bled something that was once taught as so essential to their exaltation out of them. Most mormons I have observed, when they hear about those fundamentalist groups practicing the new and everlasting covenant today, click their tongues and register their disgust with the immoral practice. Mormons, when confronted with their church’s past of polygamy, get defensive. We’ve seen that here in this thread over and over. "We don't practice polygamy! We don't believe in that! ew!" and such. It is still a part of mormonism's past and teachings. I suppose they will continue to try and phase out the teaching as much as they can as years go on but at one time it was the "new and everlasting covenant" and the confusion and backpedaling to make themselves more mainstream only helps to confirm to me the mess the LDS church is.